Web-comic updates

[mkevenaar]

Bot should be able to check for updates on the web-comic. Configurable to enable / disable, globally and one of the (current) 3 sources
Also channel should be configurable where Charlie should show the updates (per source)

Current sources:

• webtoon Webtoons - Bot permission change required to use this command! #41
• tapas Webcomics - tapas #57
• tumblr

[mkevenaar]

#3 (comment)