Updating docs/index.md

[ThiagoDiasV]

New lines added explaining how to set up Pyenv, Poetry and Selenoid Grid.

[dunossauro]

I change this commit to merge in new branch, called docs, 'cause I'm fixing the documentation and I'll try create new organization.

Something like

• Docs
• • index.md (some cool features)
• • develop.md (stuffs relative to develop tigre)
• • todos.md

[dunossauro]

merdeg :heart: