Link to built-docs instead of asciidoc file

[bmorelli25]

Now that docs are included in the APM Guide (see elastic/apm-server#6984), we should link to the docs instead of the asciidoc file.

[ghost]

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• Start Time: 2022-01-05T18:26:33.464+0000

• Duration: 7 min 58 sec

• Commit: b7d4a34

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Test	Results
Failed	0
Passed	78
Skipped	0
Total	78

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[astorm]

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