v2.86

• add contributing guidelines
• update ui status when connectivity changes
• update to whatsmeow 20220912
• reformat source code
• corrected time include problem
• improved emoji support
• add instructions to build on Fedora
• fixes #69 - update doc with new build dependencies
• add installation of golang for linux/ubuntu build instructions
• add telegram support to show chat member leaving group
• fixes #63 - add support for custom attachment open command
• fixes #67 - add support for external file picker
• improved telegram attachment cache handling
• enable experimental whatsapp support by default
• telegram to support re-downloading attachment after file cache cleanup