Replace references to 'JIRA' with 'GitHub'

Author: Philippus

contribute/guide.md

@@ -54,12 +54,12 @@ unencumbered by copyrights or patents.
 
 This is the impatient developer's checklist for the steps to submit a bug-fix pull request to the Scala project. For more information, description and justification for the steps, follow the links in that step. Further specific instructions for the release of Scala you are targeting can be found in the `CONTRIBUTING.md` file for that [github branch](https://github.com/scala/scala)
 
-1. [Select a bug to fix from JIRA](/contribute/#community-tickets), or if you found the bug yourself and want to fix it, [create a JIRA issue](/contribute/bug-reporting-guide.html) (but please
+1. [Select a bug to fix from GitHub](/contribute/#community-tickets), or if you found the bug yourself and want to fix it, [create a GitHub issue](/contribute/bug-reporting-guide.html) (but please
 [make sure it's not a duplicate](/contribute/bug-reporting-guide.html#reporting-confirmed-bugs-is-a-sin)).
 2. Optional ([but recommended](/contribute/scala-internals/#why-its-a-good-idea)), announce your intention to work on the bug on [Scala Contributors](https://contributors.scala-lang.org/). After all, don't you want to work on a team with
 [these friendly people](/contribute/hacker-guide.html#1-connect) - it's one of the perks of contributing.
 3. [Fork the Scala repository](/contribute/hacker-guide.html#fork) and clone your fork (if you haven't already).
-4. [Create a feature branch](/contribute/hacker-guide.html#branch) to work on: use the branch name `issue/NNNN` where NNNN is the JIRA issue number.
+4. [Create a feature branch](/contribute/hacker-guide.html#branch) to work on: use the branch name `issue/NNNN` where NNNN is the GitHub issue number.
 5. [Fix the bug, or implement the new small feature](/contribute/hacker-guide.html#implement), include new tests (yes, for bug fixes too).
 6. [Test, rinse](/contribute/hacker-guide.html#test) and [test some more](/contribute/partest-guide/) until [all the tests pass](/contribute/hacker-guide.html#verify).
 7. [Commit your changes](/contribute/hacker-guide.html#commit) to your feature branch in your fork. Please choose your commit message based on the [Git Hygiene](https://github.com/scala/scala#user-content-git-hygiene) section of the Scala project README.

contribute/scala-standard-library-api-documentation.md

@@ -22,7 +22,7 @@ contribution steps and guidelines. Thank you.*
 
 Since API documentation is located in Scala source code files, the
 process for contributing API documentation is similar to that of contributing bug-fixes
-to the Scala code base, but without the requirement that there be an issue filed on JIRA
+to the Scala code base, but without the requirement that there be an issue filed on GitHub
 first. When forking/branching, just use a `scaladoc/xxxx` branch name, where xxxx is a
 descriptive, but short branch name (e.g. `scaladoc/future-object`).
 However, if an issue *does* exist, please use `issue/NNNN`, where NNNN is the ticket number,
@@ -78,9 +78,9 @@ Please familiarize yourself with the following before contributing
 new API documentation to save time, effort, mistakes and repetition.
 
 * [Forking the Repo](./hacker-guide.html#set-up) - follow the setup steps through
-  the Branch section. If providing new documentation related to an existing JIRA issue, use `issue/NNNN`
+  the Branch section. If providing new documentation related to an existing GitHub issue, use `issue/NNNN`
   or `ticket/NNNN` as the guide states. If providing API documentation with no associated
-  JIRA issue, use `scaladoc/xxxx` instead.
+  GitHub issue, use `scaladoc/xxxx` instead.
 * [Scaladoc for library authors](http://docs.scala-lang.org/overviews/scaladoc/for-library-authors.html)
   covers the use of scaladoc tags, markdown and other features.
 * [Scaladoc's interface](http://docs.scala-lang.org/overviews/scaladoc/interface.html)

contribute/tools.md

@@ -86,7 +86,7 @@ The links below are to a number of Scala build and IDE related projects that are
 
 Since these tools are in separate projects, they may (and likely will) have their own rules and guidelines for contributing. The [Hacker Guide](/contribute/hacker-guide/) and [Bug-fixing](/contribute/guide/) pages will likely have much in the way of related information on how to contribute to these projects, and are recommended reading. You should also check the README.md and (if it's present) CONTRIBUTING.md files from the actual projects before contributing to them.
 
-Typically, issues for these projects will be reported and kept in the github project issue tracker for that project rather than in the Scala project JIRA.
+Typically, issues for these projects will be reported and kept in the GitHub project issue tracker for that project rather than in the Scala bug tracker.
 Many of these projects have a <a href="https://gitter.im">gitter</a> channel (usually listed in the README or CONTRIBUTING documents) which is a great place to discuss proposed work before commencing.
 
 There are some projects in this section that are in