Added markdown with atx style headers, can be chosen as
alternative markdown template on the cli.
The existing 'markdown' template will still default to
setext-style headers.
Formatters have been classes so far which contained some data (the
tamplate to use for formatting and the annotations and documents to
format) and the actual formatting logic (an execute function).
However, we can inject the annotations to be formatted and the templates
so far are static only, so they can be simple variables (we can think
about how to inject them at another point should it come up, no
bikeshedding now).
This way, we can simply pass around one function per formatter, which
should make the code much lighter, easier to add to and especially less
stateful which means less areas of broken interactions to worry about.
Added formatter for csv-compatible syntax. The formatting is quite basic
with no escaping happening should that be necessary. However, for an
initial csv output it suffices for me.
Formatters (previously templates) were pure data containers before,
continating the 'template' for how things should be formatted using
mustache. The formatting would be done a) in the exporters and b) in the
annotations.
This spread of formatting has now been consolidated into the Formatter,
which fixes the overall spread of formatting code and now can coherently
format a whole output instead of just individual annotations.
A formatter contains references to all documents and contained
annotations and will format everything at once by default, but the
formatting function can be invoked with reference to a specific
annotated document to only format that.
This commit should put more separation into the concerns of exporter and
formatter and made formatting a concern purely of the formatters and
annotation objects.
