Setting a global for g:vimwiki_version doesn't seem too egregious, and
lets us reference it cleanly elsewhere.
Removes version header from vimwiki.txt and hardcoding in tagfile
generation.
There's still one instance of that left in test/tag.vader that we should
clean up eventually.
This:
- Changes version number everywhere I could find it.
- Reworks get_version() to dispense with stable / dev division.
- Rewrites CONTRIBUTING.md to describe a new release workflow.
The development/release workflow stuff could use some thought. It's
clunky at best. There's sort of an inherent tension between semver-style
version numbers and the rolling release thing - maybe we should just use
commit hash or something date-based?
Still, it's a start.
Refaction:
- Add g:vimwiki_syntax_list to set syntaxlocal variables
- Delete: syntax/vimwiki_markdown.vim and friends
- Change: vimwiki_syntax_variables -> vimwiki_syntaxlocal_vars for consistency
- Include: some doc in design notes