Add Text-File Now Playing Method

[Coolguy3289]

Proposed changes:

• Adds another method for users to obtain now playing info.
• This was brought up in a stale issue, and is being documented for posterity as it's a decent alternative option to existing now-playing

[gAlleb]

Now that is strange) I've already made a PR.

Also note I've made amendments to my initial code to send only title when artist is empty. So no need to double it.

def write_txt(m) =

  if m["artist"] != "" then
    ignore(file.write(data="#{m[\"artist\"]} - #{m[\"title\"]}", append=false, "/var/azuracast/www/web/static/nowplaying.txt"))
  else
    ignore(file.write(data="#{m[\"title\"]}", append=false, "/var/azuracast/www/web/static/nowplaying.txt"))
  end

end
radio.on_metadata(write_txt)

https://github.com/AzuraCast/azuracast.com/pull/103

[Coolguy3289]

Updated my code snippet to match your artist check! As mentioned on Discord, I wasn't paying attention to whether a PR was made already in reference to this discussion. That being said I attempted to write my PR with the same consistency of styling currently used by the existing methods on this page, including adding some brief advantages/disadvantages of using this method.

[BusterNeece]

Not necessary; see #103.