Fluid: Move things from the Wiki

[sypets]

Move (and update / delete) content from Wiki:

• [ ] https://wiki.typo3.org/Fluid
• [ ] https://wiki.typo3.org/Fluid_Inline_Notation
• [ ] https://wiki.typo3.org/FluidSyntax

When moving please make sure to always:

• add a link to new content
• always add the category Moved: [[category: Moved]]

see: https://wiki.typo3.org/WikiMigration

[susannemoog]

Moved by Lina as part of https://github.com/TYPO3-Documentation/T3DocTeam/issues/154 - closing this one here.