[FW][REF] l10n: PoC doc restructure for CO

[fw-bot]

Cherry pick of #2659, now pointing to the correct base branch.

@StraubCreative and @samueljlieber found the latam l10n docs could use an update/cleanup to break apart the single long-form article for each l10n module.

This PR was created as a proof of concept to improve the structure of latam l10n docs so they are more consumable and follow a similar flow to the rest of the documentation. The proposed document structure is for Colombia only in this PR, although this structure applies to all latam l10n countries.

The details of the proposed document structure can be found here, the structure is summarized below:

localizations
└── colombia
└── colombia.rst
..........├── configuration
..........├── reports
..........├── workflows
..........├── configuration.rst
..........├── reports.rst
..........└── workflows.rst

colombia.rst is the main l10n doc providing an introduction, video tutorials, scope, and glossary of terms.
|_ configuration.rst outlines the steps to install the localization module and the basic configuration setup.
|_ workflows.rst outlines the main workflows of the module, common problems/errors, and more advanced workflows.
|_ reports.rst outlines the financial reporting process of the module.

Each nested RST doc contains it's own media folder with the same name.

The goal is to build a working model, and then replicate + keep this consistent structure throughout latam l1on docs.

EDIT: summarized doc structure, removed configuration doc/folder, merged content into colombia.rst per the ideal User Doc Structure guidelines.

Forward-Port-Of: #5466
Forward-Port-Of: #3167

[robodoo]

Pull request status dashboard.

[fw-bot]

This PR targets saas-15.2 and is part of the forward-port chain. Further PRs will be created up to master.

More info at https://github.com/odoo/odoo/wiki/Mergebot#forward-port

[fw-bot]

@StraubCreative @jcs-odoo the next pull request (#5472) is in conflict. You can merge the chain up to here by saying

@fw-bot r+

More info at https://github.com/odoo/odoo/wiki/Mergebot#forward-port

[jcs-odoo]

@fw-bot r+