Add towncrier (#2873)

* Adds towncrier as our changelog system.
* Updates our contributor guidelines for this.

Resolves #2872

make.bat

@@ -30,6 +30,12 @@ goto syncenv
 .\.venv\Scripts\python -m pip install -Ur .\tools\dev-requirements.txt
 exit /B %ERRORLEVEL%
 
+:checkchangelog
+REM This should be written for windows at some point I guess.
+REM If we can swith to powershell, it can make this much easier.
+echo This doesn^'t do anything on windows ^(yet^)
+exit /b 0
+
 :help
 echo Usage:
 echo   make ^<command^>