Value: produce free software

See https://talk.libreho.st/t/value-produce-free-software/121

mentioned in merge request !4 (closed)

Note that if this issue is closed by merging !4 (closed), it requires that we update other parts accordingly, notably:

• https://talk.libreho.st/t/welcome-banner/46
• https://talk.libreho.st/t/cpp-commitments-policies-and-processes/158
• and close https://talk.libreho.st/t/value-produce-free-software/121

mentioned in commit 3a360f31