Git ignore hidden files with defined exceptions (#7108)

* git ignore all hidden files

* Removal file with non-existent link

* git Ignore all hidden files except .gitignore

* Set exceptions in gitignore

.gitignore

@@ -1,5 +1,11 @@
 # file types to ignore
-
+.*
+!/.gitignore
+!/.travis/
+!/.travis.yml
+!/.clang-format
+!/.git-blame-ignore-revs
+!/.gitattributes
 *.DS_Store
 *.pyc
 *.obj
@@ -34,10 +40,7 @@ install_manifest.txt
 /src/Tools/offlinedoc/localwiki/
 /src/Tools/offlinedoc/*.txt
 OpenSCAD_rc.py
-/\.idea/
-.tags
 tags
-/\.vscode/
 
 # crowdin file
 src/Tools/freecad.zip