Add --parser option to specify import path

[jnothman]

A library can now create (or extend) a parser in a module of their choice such that doc2dash --parser mymodule.MyParser path will build with that parser, avoiding the need for autodetection strategies

[codecov]

Codecov Report

Merging #60 into master will decrease coverage by -3.79%.
The diff coverage is 47.82%.

@@            Coverage Diff             @@
##           master      #60      +/-   ##
==========================================
- Coverage     100%   96.21%   -3.79%     
==========================================
  Files           7        7              
  Lines         299      317      +18     
  Branches       39       40       +1     
==========================================
+ Hits          299      305       +6     
- Misses          0       11      +11     
- Partials        0        1       +1

Impacted Files	Coverage Δ
src/doc2dash/main.py	91.17% <47.82%> (-8.83%)	❌

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[codecov]

Codecov Report

Merging #60 into master will not change coverage.
The diff coverage is 100%.

@@          Coverage Diff          @@
##           master    #60   +/-   ##
=====================================
  Coverage     100%   100%           
=====================================
  Files           7      7           
  Lines         309    327   +18     
  Branches       40     42    +2     
=====================================
+ Hits          309    327   +18

Impacted Files	Coverage Δ
src/doc2dash/__main__.py	100% <100%> (ø)	⬆️

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Δ = absolute <relative> (impact), ø = not affected, ? = missing data
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[jnothman]

Again flake8 is the only failure.

[hynek]

This needs a changelog entry and a docs update (usage.rst). Thanks!

[hynek]

Thanks!