• updated signal-cli to v0.13.20
• added possibility to change permissions with the groups PUT request
• added possibility to change the send messages permission when creating
  a group with the POST request
• added new remote-delete endpoint (thanks to @Era-Dorta)
• whitespaces in phone numbers do not result in validation errors anymore
• added new env variable SIGNAL_CLI_CHOWN_ON_STARTUP - which skips the chown on startup (thanks to @WKeaganW)
• added missing description parameter to the link preview payload
• various documentation improvements (thanks to @jakommo, @f2calv, @CodeShellDev, @Era-Dorta)