feat: expose parser writer opts

[s-h-a-d-o-w]

Let's see whether using the same branch as here will just work out of the box. 🙂

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Exposing these will resolve a number of issues where people want to customize something but don't want to create a full preset to replace the default one with.

Functionally, if these overrides aren't set, their value will obviously be undefined, making this change fully backwards compatible.

Two examples about a simple sorting override:
Fixes conventional-changelog#293
Fixes conventional-changelog#869

(I also tweaked pieces of the docs that seemed excessive to me - linking to the same thing and mentioning how customizable everything is multiple times. 😅)

BEGIN_COMMIT_OVERRIDE
feat(options): Expose parser and writer options from conventional-commits-parser and conventional-commits-writer
END_COMMIT_OVERRIDE

[codecov-commenter]

Codecov Report

Merging #37 (4bed054) into master (7b7ed56) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master      #37   +/-   ##
=======================================
  Coverage   97.62%   97.62%           
=======================================
  Files          26       26           
  Lines        1178     1178           
=======================================
  Hits         1150     1150           
  Misses         28       28           

Impacted Files	Coverage Δ
lib/lifecycles/changelog.js	100.00% <ø> (ø)

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[TimothyJones]

Thanks for this! Thanks also for improving the documentation as you went - I really appreciate it!

I noticed that the docs still mention standard-version in a couple of places - but it turns out not just in the places that you changed (oops), so I'll fix that in a subsequent commit.

[TimothyJones]

Also thanks for the kind words about Pact-JS! It's really nice to know it was helpful <3

[TimothyJones]

Released in 10.1.0.