The help text for uploading certificates in the Mexican localization has been updated to correctly specify .cer and .key file formats instead of the confusing DER format reference. This change makes it clearer for users in Mexico what file types they need to upload when setting up their electronic invoicing certificates.

Currently, help message for certificates in mexican localization ask for der format files. This can be confusing, therefore this commit aims to change that for smoother user understandings.

[Here](https://www.odoo.com/documentation/17.0/applications/finance/fiscal_localizations/mexico.html#cer-and-key-certificates) is the link to the documentation specifying the format are .cer and .key

The knowledge module's history revision tour has been updated to align with recent improvements made to the document comparison feature. This ensures the guided tour accurately reflects the current functionality and provides users with an up-to-date learning experience when reviewing document history.

Adapt history revision tour after the improvements done on the comparison feature.

task-3761721