Add legacy urls to dead-links checker

[madebyrogal]

Overview

Our documentation's structure is changing quite often so to track if old links, that where published before in 3rd party platforms, social media or in botkube itself, still working we need to have a list of them and possibility to check 404 errors.

The solution won't be perfect (because tracking all changes will be tedious task) but at least this solution give us a hand on most cases.

AC

• extend this script magefiles/magefile.go#23 (CheckDeadLinks) to check additional markdown (e.g. - archive-links.md)
• provide archive-links.md markdown with old links, that needs to be supported.

[madebyrogal]

@mszostok you had a list (not sure if you still have it, but it will be good for start)

[mszostok]

Yes, here are the legacy URLs:

• https://botkube.io/docs

• https://botkube.io/privacy#privacy-policy

• https://botkube.io/filters

• https://botkube.io/installation/

• https://botkube.io/configuration/resource/

• https://botkube.io/configuration/communication/

• https://botkube.io/installation/slack/#install-botkube-slack-app-to-your-slack-workspace

• https://botkube.io/configuration/communication/#source-and-executor-bindings

• https://botkube.io/docs/installation/slack/#install-botkube-slack-app-to-your-slack-workspace

• https://botkube.io/docs/installation/socketslack/#obtain-bot-token

• https://botkube.io/docs/installation/socketslack/#generate-and-obtain-app-level-token

• https://botkube.io/docs/configuration/source

• https://botkube.io/docs/installation/slack/

• https://botkube.io/docs/installation/discord/#install-botkube-to-the-discord-server