fix(docs-app): remove stopWordFilter from lunr pipeline

[flakolefluk]

Description:
This PR removes the stopWordFilter from the lunr pipeline. It filters words like "of" and "from" when indexing, missing some operators or functions when searching.

https://github.com/olivernn/lunr.js/blob/master/lib/stop_word_filter.js

Related issue (if exists):
Fixes #4524

[coveralls]

Pull Request Test Coverage Report for Build 8062

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 5 unchanged lines in 3 files lost coverage.
• Overall coverage increased (+0.2%) to 96.962%

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Files with Coverage Reduction	New Missed Lines	%
src/internal/observable/fromPromise.ts	1	87.5%
src/internal/observable/fromIterable.ts	2	95.24%
src/internal/observable/fromObservable.ts	2	83.33%

Totals
Change from base Build 8053:	0.2%
Covered Lines:	5777
Relevant Lines:	5958

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💛 - Coveralls

[niklas-wortmann]

I need to test that manually very quick. I'll do my best to do it asap. I'll let you know. But thanks for contributing!

[niklas-wortmann]

oh wow well spotted. It works great!

[flakolefluk]

awesome! thanks for reviewing it :)

[ladyleet]

hi @flakolefluk !!!!!!

[ladyleet]

hey @jwo719 @benlesh - @flakolefluk is joining our team next week!