Refactor CI/CD

[TessFerrandez]

• Move CI/CD into one section
• Restructure the folders and files so it's a bit more streamlined, moving recipes into recipes etc.
• Adding the why and the fundamentals
• Fixing links

[github-actions]

🦙 MegaLinter status: ⚠️ WARNING

Descriptor	Linter	Files	Fixed	Errors	Elapsed time
✅ MARKDOWN	markdownlint	33		0	1.56s
⚠️ MARKDOWN	markdown-table-formatter	33		1	0.32s
✅ MDLINKCHECK	linkcheck	33		0	8.31s
✅ SPELL	cspell	36		0	3.61s
✅ YAML	prettier	2		0	0.58s
✅ YAML	yamllint	2		0	0.21s

See detailed report in MegaLinter reports
Set VALIDATE_ALL_CODEBASE: true in mega-linter.yml to validate all sources, not only the diff

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[Doommius]

approved with suggestions

[TessFerrandez]

Merging with only 1 approver - as per conversation with @nyouens and EF team