improve the issue templates

1. Shortened the prefixes for fix-able issues
2. Converted the content so that they can be copy-pasted verbatim to the issue tracker (without the need to be displayed raw)

.github/template-bugReport.md

@@ -1,30 +1,18 @@
-**Bug Report**
+**Issue Title:** Bug: [brief description of bug]
 
-**Issue Title:** Bug Report: [Brief description of bug]
+Copy-and-paste the following content to the issue tracker and fill in with relevant details:
+```markdown
+**Tell us what environment you encountered the bug on, e.g. live server at `V5.93`, `master` branch at commit 1234567.**
 
-**Environment (dev/staging/live, version)**
 
-> Tell us what environment you encountered the bug on,
->
-> e.g. live server at `V5.93`
->
-> e.g. `master` branch at commit 1234567
 
-**Steps to Reproduce**
+**Tell us the steps to reproduce the bug.**
+
 
-> Help us to reproduce the bug on our end so we can fix it, e.g.
-> 
-> 1. Login as an student on the mobile website.
-> 1. Click 'Comments' in the menu.
 
 **Expected Behaviour**
 
-> Tell us what you expected to happen after the steps detailed above,
->
-> e.g. Clicking on 'Comments' was supposed to bring me to the 'Comments' page.
 
-**Actual Behaviour**
 
-> Tell us what actually happened,
->
-> e.g. Nothing happened
+**Actual Behaviour**
+```

.github/template-contributorIntro.md

@@ -1,19 +1,13 @@
-**New Contributor Introduction**
-
 **Issue Title:** New Contributor Self-Intro [your real name]
 
-**Link to my app:**
-
->Add the link to your TEAMMATES staging site here, e.g. `https://teammates-username.appspot.com`
-
-**Link to my fork:**
-
->Add the link to your TEAMMATES fork here, e.g. `https://github.com/username/teammates`
+Copy-and-paste the following content to the issue tracker and fill in with relevant details:
+```markdown
+- **Link to your app:** e.g. https://teammates-username.appspot.com
+- **Link to your fork:** e.g. https://github.com/username/teammates
 
-**Screenshot of change**
+**Post a screenshot of changes you did (as seen on the UI).**
 
->Post the screenshot of changes you did (as seen on the UI).
 
-**Real name and a short self-introduction**
 
->Tell us your real name and give a short self-introduction, e.g. your education background, why you want to contribute to TEAMMATES, etc.
+**Tell us your real name and give a short self-introduction, e.g. your education background, why you want to contribute to TEAMMATES, etc.**
+```

.github/template-featureRequest.md

@@ -1,23 +1,18 @@
-**Feature / Enhancement Request**
+**Issue Title:** Feature: [your request in a line] OR Enhancement: [your suggestion in a line]
 
-**Issue Title:** Feature Request: [your request in a line]
+Copy-and-paste the following content to the issue tracker and fill in with relevant details:
+```markdown
+**Describe the feature/enhancement you would like to see added to TEAMMATES.**
 
-**Proposed Feature / Enhancement**
 
-> Give us a brief description of the feature / enhancement you would like to see added to TEAMMATES,
->
-> e.g. A mobile web app for TEAMMATES
 
-**Problem it solves**
+**How would your proposed feature/enhancement benefit TEAMMATES?**
 
-> Tell us how your proposed feature / enhancement will benefit TEAMMATES,
->
-> e.g. Many students use TEAMMATES on their phones and the current mobile version is not ideal because...
 
-**Developer/User-facing**
 
-> Let us know if the proposed feature is for the benefit of the developer or user
+**Are there existing similar features? If yes, why do they fall short of your expectations?**
 
-**Existing similar features (if any), and their shortcomings**
 
-> Let us know if there already are similar features in TEAMMATES, and why they fall short of your expectations
+
+**Is the proposed feature/enhancement for the benefit of developers or users?**
+```

.github/template-helpRequest.md

@@ -1,64 +1,21 @@
-**Help Request**
-
 **Issue Title:** Help Request: [summary of your problem]
 
-* **Operating System:**
-* **JDK Version:**
-* **Eclipse Version:**
-* **Firefox / Chrome Version (where applicable):**
-
-**Step in the `settingUp.md` Guide / Failing Tests**
-
-*If you are setting up the project:*
-
-> Tell us the step in the setting up guide at which you are stuck
+Copy-and-paste the following content to the issue tracker and fill in with relevant details:
+```markdown
+- **Operating System:**
+- **JDK Version:**
+- **Eclipse Version:**
+- **Firefox / Chrome Version (where applicable):**
 
-*If you are resolving test failures:*
+**Tell us what you were trying to do / what you need help with.**
+- e.g. if you were setting up the project, tell us the step in the setting up guide at which you are stuck.
+- e.g. if you were resolving test failures, tell us which tests are failing.
 
-> Tell us which tests are failing
 
-*Miscellaneous*
 
-> Tell us what you were trying to to / what you need help with
+**Provide us with more relevant information, such as screenshot, error stack traces, or console messages.**
 
-**Error Messages Shown...**
 
-*...in the TestNG tab, if you are resolving test failures:*
 
+**Tell us the steps you have taken to try to solve the problem.**
 ```
-java.lang.AssertionError:
-        at org.testng.AssertJUnit.fail(AssertJUnit.java:59)
-        at org.testng.AssertJUnit.assertTrue(AssertJUnit.java:24)
-        at org.testng.AssertJUnit.assertNotNull(AssertJUnit.java:267)
-        at org.testng.AssertJUnit.assertNotNull(AssertJUnit.java:259)
-        at teammates.test.cases.BaseTestCase.assertNotNull(BaseTestCase.java:177)
-        at teammates.test.cases.action.AdminAccountDeletePageActionTest.testExecuteAndPostProcess(AdminAccountDeletePageActionTest.java:42)
-```
-
-*...in the Console, for other cases:*
-
-```
-java.lang.reflect.InvocationTargetException
-        at com.google.appengine.runtime.Request.process-e60877bf1213698c(Request.java)
-        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
-        at teammates.ui.controller.InstructorFeedbackQuestionEditAction.validateQuestionGiverRecipientVisibility(InstructorFeedbackQuestionEditAction.java:132)
-        at teammates.ui.controller.InstructorFeedbackQuestionEditAction.editQuestion(InstructorFeedbackQuestionEditAction.java:80)
-        at teammates.ui.controller.InstructorFeedbackQuestionEditAction.execute(InstructorFeedbackQuestionEditAction.java:52)
-        at teammates.ui.controller.Action.executeAndPostProcess(Action.java:344)
-        ...
-Caused by: java.lang.AssertionError: Contrib Qn Invalid visibility options
-        at teammates.common.util.Assumption.fail(Assumption.java:61)
-        at teammates.common.util.Assumption.assertTrue(Assumption.java:29)
-        at teammates.common.datatransfer.FeedbackContributionQuestionDetails.validateGiverRecipientVisibility(FeedbackContributionQuestionDetails.java:755)
-        ... 36 more
-```
-
-**How You Tried Solving the Problem**
-
-> Tell us the steps you have taken to solve the problem
->
-> e.g. I deleted everything and started over, but the exact same problems occurred at step 3
-
-**Screenshots (recommended)**
-
-> Include a screenshot of what you are having trouble with to help us help you