Clarify readme and contributing documentation (#105, #155)

• Fix documentation link
• Improve first installation step
• Remove black §, covered into pre-commit §
• Merge contributing from readme into contributing.md
• readme: Remove need for Poetry to run examples
• readme: Add missing requirements

Close #105 (closed), #155 (closed).

changed milestone to %1.2.0

added Doc/Website Install labels

assigned to @moul

added 1 commit

• 53bb85b9 - readme: Add missing requirements

Compare with previous version

changed the description

requested review from @vtexier

approved this merge request

merged