Links the "Home vs Away" text to the match page.

This looks a lot cleaner in the channel then the full url.
Allows the bot name to be customized

Just like the channel, hook and language. This adds an environment
vairable called `BOTNAME` that defaults to "WorldCupBot".

Also updates the README with the new setting.
Merge pull request #14 from Cyborg572/custom_bot_name

Allows the bot name to be customized
Merge pull request #13 from Cyborg572/clean_link

Links the "Home vs Away" text to the match page.