added link to docs in the changelog

tweaked gem description wording

release 0.7.0

fixed Skyfall::Firehose::Message for Ruby < 3.2

updated comment about IdentityMessage handle

run CI on all rubies from 2.6 to 4.0

added irb to Gemfile

added rev, since and prev_data to CommitMessage

updated readme & changelog

added #blocks and field checks to SyncMessage

tweaks to CAR section parsing behavior

decode CAR sections lazily

optimized check_if_not_nil further

Use Time.iso8601 / Time.new to parse Time

fixed check_if_not_nil to avoid unnecessary string allocations