documentation

Pull request #2905: feature/DEV-4324-7.3-D. minimum supported Go version raised.

Merge in WEB/documentation from feature/DEV-4324-7.3-D to release/7.4

* commit '2ef232aafd598dd010df222ad2bec52ad406886e':
  [DEV-4324] restructured Go requirement for agent2 & web service
  [DEV-4324] added link to new "Upgrade notes" entry
  [DEV-4324] added "Go version for source builds" entry in "Upgrade notes"
  [DEV-4324] converted Go library lists to go.mod links
  [DEV-4324] unified all mentions of supported Go version