Automation Request: Replace reference to EIP and ECIP with links

[BelfordZ]

It's very common for discussion in issues and pull requests for people to refer to an EIP or ECIP by number. I find it very annoying to have to look up the eip everytime I don't remember the number -> topic.

This issue is to suggest a github bot that would:

1. listen to issue and pull request comments
2. find references to [eip|ecip][\space|-][number]
3. edit the comment, replace it with a link to the ecip or eip

The bot should be runnable from anyones account, and since we are able to edit each others comments, it should be fairly straightforward for permissions.