docs: Add detailed text styling information

docs: Add detailed text styling information

Summary:
More detailed descriptions for each attribute.
Relationship between attributes.
Default values.
Links to direct API methods for the corresponding property.
General text overhaul and formatting.

Test Plan: Builds and passes tests. Generate docgen or DocFX documentation and enjoy your new Text styling descriptions!

Reviewers: ali.alzyod

Reviewed By: ali.alzyod

Subscribers: AbdullehGhujeh, cedric, #reviewers, #committers, woohyun, bu5hm4n

Tags: #efl

Differential Revision: https://phab.enlightenment.org/D10873