Base: Add filetype-json icons

Author: https://github.com/linusg
Commit: https://github.com/SerenityOS/serenity/commit/df9fe8fa7b0
Pull-request: https://github.com/SerenityOS/serenity/pull/4085
Reviewed-by: https://github.com/alimpfard
Reviewed-by: https://github.com/awesomekling

Base/etc/FileIconProvider.ini

@@ -7,6 +7,7 @@ html=*.html,*.htm
 ini=*.ini
 java=*.java
 javascript=*.js,*.mjs
+json=*.json
 library=*.so,*.a
 markdown=*.md
 music=*.midi