Docs: improvements for "references - phpdoc - tags - deprecated"
Docs: improvements for "references - phpdoc - tags - deprecated"

Syntax:
* Replaced "version" with "Semantic Version" as per PSR 19.

Description:
* Combined existing text with the current description in PSR-19 with minor adjustments for clarification.

Other:
* Minor inline markup and grammar fixes.
* Made the syntax outline a code block.
* Linked some text to related other documentation pages.

Ref: https://github.com/php-fig/fig-standards/blob/master/proposed/phpdoc-tags.md#54-deprecated

phpDocumentor/phpDocumentor2,phpDocumentor/phpDocumentor2,phpDocumentor/phpDocumentor2,phpDocumentor/phpDocumentor2