[User Story] As a developer, I want to be able to make issue references inside project channels

[srjheam]

Given...
Given I accept the bot to overwrite my messages with issue references (by a command like c!github iss-ref true)

When...
When I send a message with a issue reference in a project channel.

We shall fix #69 and merge #70 quickly

Then...
Then the bot copy my message, deletes it and resend referencing the issue. (using a hyperlink)

[{user}]: We shall fix [#69](https://github.com/Code2Gether-Discord/{channel}/issue/69) and merge [#70](https://github.com/Code2Gether-Discord/{channel}/pull/70)