Hi, I'm a new vim user so sorry if this is a silly mistake. With Vundle installed I added

Plugin 'https://github.com/elzr/vim-json'

to my .vimrc file, wrote the file, reloaded .vimrc with :source, ran :PluginInstall and opened a json file. But I can't see any of the highlighting, warnings or concealing.

Is this something that you could help me fix? Thanks!