Automatically install software - Documentation

[sharon-fdm]

Clarify that adding software in Fleet makes it "available for install." And explain the two ways to install:
- manually install for an individual host
- go to Host details page and click "install"
- or self-service via "My device" page
- install automatically
- go to Policies page and have a policy failure trigger it

"How to use":

1. Add package to your software that's available for install
2. Manually install it on your test host
3. Get ready to install automatically: write a policy query to check for the minimum version. If the host doesn't have that version

• SOFTWARE_NAME and SOFTWARE_VERSION comes from the data in host vitals (step 2)

4. Add package to the policy under Manage automations

• Any existing policy pass/fail counts are cleared to reset the software install trigger

Here are the templates:

deb:
	SELECT 1 FROM deb_packages WHERE name = '<SOFTWARE_NAME>' AND version_compare(version, '<SOFTWARE_VERSION>') >= 0;

pkg:
	SELECT 1 FROM apps WHERE name = '<SOFTWARE_NAME>' AND version_compare(bundle_short_version, '<SOFTWARE_VERSION>') >= 0;

msi/exe:
	SELECT 1 FROM programs WHERE name = '<SOFTWARE_NAME>' AND version_compare(version, '<SOFTWARE_VERSION>') >= 0;

[lucasmrod]

This issue seems to be a duplicate of #21842.

Noah recently edited #21842 to explain how users would use the feature (at a high level).

[lucasmrod]

I've moved the description from #21842 to this issue which had a blank description.

[fleet-release]

Software installs smooth,
Like clouds in glass city float,
Ease for users, true growth.