EI Pages in 2.0.0-maintainance branch point to documentation on the master

Description

Some of the documentation in 2.0.0-maintainance branch points out to the master branch which doesn't exist

Motivation

Updated documentation pointing out to proper branches and reachable documentation pages.

Exemplification

Here is an example of such page : https://github.com/eiffel-community/eiffel-intelligence/blob/2.0.0-maintenance/wiki/markdown/rules.md#Rule-set-up

Under the History Rules, when you click the here it points out to the master branch and that documentation is not available, instead it should point out to the 2.0.0-maintainance branch documentation itself.

Benefits

Readability of documentation and pointing out to the correct version of the documentation.

Possible Drawbacks

Unreachable pages and confusion to users on the documentation