Remove webpack-generated demo files from git tracking

- Add dist/fonts/, demo JS files, and webpack artifacts to .gitignore
- Remove committed bootstrap-icons fonts (generated by webpack)
- Remove committed app.js, jquery.js and related files (generated by webpack)
- These files should be generated locally via 'npx webpack' and not committed

.gitignore

@@ -1,3 +1,10 @@
 node_modules
 test/instrumented/
-*.nupkg
+*.nupkg
+dist/fonts/
+dist/app.js
+dist/app.js.map
+dist/app.js.LICENSE.txt
+dist/jquery.js
+dist/jquery.js.map
+dist/jquery.js.LICENSE.txt