* scripts: add set-more-info-link.py
* scripts/set-more-info-link.py: use current tldr repo if the script is being run from scripts/
* scripts/set-more-info-link.py: allow passing .md extension
* scripts/set-more-info-link.py: differentiate between links added and updated
* set-more-info-link.py: make omitting .md optional, rather than adding it optional
* set-more-info-link.py: make IGNORE_FILES a tuple rather than a str
