Replace local web server setup for web editor with a Python-based solution

This makes it easier to set up, as you always have Python installed
when building Godot. On the other hand, you don't always have Node.js
+ npm installed (and you may not want to spend time running `npm install`).

Co-authored-by: Fabio Alessandrelli <fabio.alessandrelli@gmail.com>

.gitignore

@@ -82,9 +82,9 @@ platform/android/java/*/libs/
 # iOS
 *.dSYM
 
-# Javascript
+# Web platform
 *.bc
-platform/javascript/node_modules/
+platform/web/node_modules/
 
 # Misc
 *.debug