HPA docs

[MattiasGees]

What this PR does / why we need it:
This adds HPA docs to the example section

Which issue this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close that issue when PR gets merged): fixes #

Special notes for your reviewer:

Release note:

NONE

[jetstack-bot]

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[MattiasGees]

/assign @dippynark
/unassign

[jetstack-bot]

@MattiasGees: The following test failed, say /retest to rerun them all:

Test name	Commit	Details	Rerun command
tarmak-puppet-module-tarmak-acceptance-1-14-centos	d7184f1	link	/test puppet-tarmak-acceptance-centos v1.14

Full PR test history. Your PR dashboard. Please help us cut down on flakes by linking to an open issue when you hit one in your PR.

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