Updated .gitignore

- Makes a clear distinction between files and directories, don't ignore build files
- Added some file types and directories
- ignore also 'lite-xl' prefixed install directories other than the executable

.gitignore

@@ -1,13 +1,19 @@
-build*
-.build*
-.run*
-*.zip
-*.tar.gz
-.lite-debug.log
-subprojects/lua
-subprojects/libagg
-subprojects/reproc
-lite-xl
-error.txt
+build*/
+.build*/
+lhelper/
+submodules/
+subprojects/lua/
+subprojects/libagg/
+subprojects/reproc/
 .ccls-cache
+.lite-debug.log
+.run*
+*.diff
+*.tar.gz
+*.zip
+*.DS_Store
+*App*
+appimage*
 compile_commands.json
+error.txt
+lite-xl*