Update README.md

Author: RohitRathore1

README.md

@@ -73,3 +73,34 @@ Common prefixes:
 - feat: A new feature
 - docs: Documentation changes
 - test: Correct existing tests or add new ones
+
+#### Documentation
+- Make sure you put useful comments in your code.  Do not comment things that are obvious.
+- Please avoid creating new directories if at all possible. Try to fit your work into the existing directory structure. If you want to create a new directory, then please check if a similar category has been recently suggested or created by other pull requests.
+- If you have modified/added documentation, please ensure that your language is concise and contains no grammar errors.
+- Do not update README.md along with other changes, first create an issue and then link to that issue in your pull request to suggest specific changes required to README.md
+
+#### Test
+- Make sure to add examples and test cases in your main() function.
+- If you find any algorithm or document without tests, please feel free to create a pull request or issue describing suggested changes.
+
+### Pull Requests
+- Checkout our [pull request template](https://github.com/TheAlgorithms/C-Plus-Plus-Algorithms/blob/master/.github/pull_request_template.md)
+
+#### cpplint
+To see if [__cpplint__](https://github.com/cpplint/cpplint) is already installed, do:
+* `cpplint --version`  # currently returns "cpplint 1.4.4"
+If cpplint is ___not___ installed then do:
+* `python3 -m pip install cpplint`  # If that does not work then try...
+* `py -m pip install cpplint`  # If that does not work then try...
+* `pip install cpplint`
+Once cpplint is installed, test your file(s) with:
+* `cpplint --filter=-legal my_file.cpp my_other_file.cpp`  # Fix any issues and try again.
+
+The [__clang-format__](https://clang.llvm.org/docs/ClangFormat.html) tool can fix whitespace related _cpplint_ issues.
+* On Macs only: `brew install clang-format`  # Only needs to be installed once.
+* All platforms: `clang-format -i -style="{IndentWidth: 4}" my_file.cpp`
+
+Most importantly,
+- Happy coding!
+