Improve formatting

[djahandarie]

(Stacked PR on #188 and #189.)

This makes long issues easier to read by:

1. Using blockquotes (especially important for when new conversation happens on the issue after it's imported, to be able to easily differentiate)
2. Adding creation information on comments (resolves Cloned comments should contain original poster and link #139)
3. Rewording creation information for issues to improve scanability
4. Adding mini avatars to improve scanability

Example:

[johnmurphy01]

@djahandarie I have just merged in my PR that updates quite a bit of the main code file and also brings the google chrome extension manifest version to 3. If you would still like, please rebase and make the changes against the new codebase. Much appreciated

[johnmurphy01]

@djahandarie I've created another PR that uses some of this code