Updated .gitattributes and .gitignore, added cleanup scripts

repo-cleanup.cmd

@@ -0,0 +1,26 @@
+@ECHO OFF
+TITLE Clean up Unity Project repo
+SETLOCAL EnableDelayedExpansion
+
+CALL :cleanup --dry-run || GOTO die
+
+CHOICE /M "Execute"
+IF !ERRORLEVEL! NEQ 1 (
+	ECHO Aborting cleanup...
+) ELSE (
+	CALL :cleanup || GOTO die
+	ECHO Done.
+)
+
+:end
+PAUSE
+EXIT /B 0
+
+:die
+PAUSE
+EXIT /B %ERRORLEVEL%
+
+
+:cleanup
+	git clean -dfX %* "%~dp0." || EXIT /B
+	EXIT /B 0