Split package.

[MichaelHatherly]

Docile.jl currently relies on Markdown.jl during macro expansion time to parse docstrings into markdown ASTs. This adds to package load times and isn't really necessary since we can convert each docstring to a presentable format when calling writemime rather.

Splitting out the presentation code into a separate package (named, preliminarily, Lexicon.jl) will allow docstrings to be written in different markup, such as rst or asciidoc, once parsers are written.
A metadata field in Entry such as :format could specify what parser to use for each entry.

Storing the docstring as String rather that an AST also simplifies full text queries by not having to walk the AST; instead using contains directly.

Features that would move to Lexicon.jl include: query, @query, doctest, save, writemime.

Features that would be retained include: @doc, @docstrings, @tex_mstr.

[timholy]

This looks like a great change, thanks for being sensitive to this issue.

Just starting a new project, and I'm going to use Docile/Lexicon as I go.

[MichaelHatherly]

I've definitely found the package separation to be working out better.

Give me a shout if you encounter anything in either package that doesn't fit with your project, since I've not had the chance to try them out on anything very large yet.