[TL] - TL Variants

[MJ665]

Describe the improvement

variants documentation page for TCET Linux

Why do we need this?

To show currently available variants of TCET Linux

Do you have a proposed solution?

variants.md

Do you want to work on this feature?

• [X] I am willing to implement this feature.

Terms and Conditions

• [X] I agree to follow this project's Code of Conduct

[MJ665]

https://github.com/tcet-opensource/documentation/pull/348

Done