docs(README): add link to html-minifier options (options.minimize)

[JounQin]

Please check if the PR fulfills these requirements

• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Other... Please describe:

Other information:
As title.

[codecov]

Codecov Report

Merging #151 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #151   +/-   ##
=======================================
  Coverage   96.96%   96.96%           
=======================================
  Files           2        2           
  Lines          99       99           
  Branches       20       20           
=======================================
  Hits           96       96           
  Misses          3        3

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[michael-ciniawsky]

@JounQin Thx