docs: Update or correct default enabledPreviewProviders lists

[iasdeoupxe]

Description

See this for the current default list:

https://github.com/owncloud/core/blob/v10.15.0/lib/private/PreviewManager.php#L266-L281

and the relevant comments / examples have been ordered the same way. OC\Preview\PDF was dropped from the config.sample.php because it is not in the default enabled list.

Question:

What about these in https://doc.owncloud.com/server/10.14/admin_manual/configuration/files/previews_configuration.html#preview-format-requirements not mentioned anywhere in the updated files:

OC\Preview\AI
OC\Preview\EPS
OC\Preview\PSD
OC\Preview\TTF

Are the docs even correct. few lines in the code we can see this:

https://github.com/owncloud/core/blob/v10.15.0/lib/private/PreviewManager.php#L334-L337

Related Issue

N/A

Motivation and Context

Better documentation

How Has This Been Tested?

No testing, only documentation changes

Screenshots (if appropriate):

N/A

Types of changes

Not sure what to tick here

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Database schema changes (next release will require increase of minor version instead of patch)
• Breaking change (fix or feature that would cause existing functionality to change)
• Technical debt
• Tests only (no source changes)

Checklist:

Not sure what to tick here

• Code changes
• Unit tests added
• Acceptance tests added
• Documentation ticket raised:
• Changelog item, see TEMPLATE

[CLAassistant]

All committers have signed the CLA.

[iasdeoupxe]

Anything required / unclear?