[ES|QL] Allows searching in the documentation description

[stratoula]

Summary

Allows searching on the ES|QL reference markdown. This means that now the search will return more results. Examples:

• If I search for keep it will return all the occurences of the word keep so the user will see the keep command but also all the other commands that the keep word is used in the examples. I think that this is very useful as the user can see more than 1 examples of a command
• If I search for date it will return not only the commands that have the word date but also the commands that allow date in their arguments
• As now it searches also to the description it can also return false positive results. I think is an accepted drawback.

Note: I am not allowing this for Lens formulas. I introduced a new property to disable it. The implementation works for formulas too but we haven't received any negative feedback so far so I would like to test it in the ES|QL reference first.

Checklist

• Unit or functional tests were updated or added to match the most common scenarios

[elasticmachine]

Pinging @elastic/kibana-visualizations (Team:Visualizations)

[ninoslavmiskovic]

👍🏻 This is great @stratoula - This is going to be super helpful.

[dej611]

Tested locally with Safari and all good 👍

Let few minor code comments, but will no block it.

[mbondyra]

Very cool!

[kibana-ci]

💚 Build Succeeded

• Buildkite Build
• Commit: 9fc8362

Metrics [docs]

Module Count

Fewer modules leads to a faster build time

id	before	after	diff
lens	1141	1142	+1
securitySolution	4727	4728	+1
stackAlerts	120	121	+1
textBasedLanguages	48	49	+1
total			+4

Async chunks

Total size of all lazy-loaded chunks that will be downloaded as the user navigates the app

id	before	after	diff
lens	1.4MB	1.4MB	+477.0B
textBasedLanguages	150.5KB	151.0KB	+518.0B
total			+995.0B

History

• 💚 Build #178990 succeeded be5d448
• 💔 Build #178982 failed 2344d1b
• 💚 Build #178759 succeeded f7e82f5

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@elasticmachine merge upstream