WIP 2.19 Porting Guide stub with data tagging (#2429)

* WIP 2.19 Porting Guide stub with data tagging

* Add another multi-pass templating example

* Add example for unintentional string conversion

* Add blank lines after code blocks

* Fix heading type

* Attempt to fix warnings

* add conditional syntax error example

* Update docs/docsite/rst/porting_guides/porting_guide_core_2.19.rst

Co-authored-by: Maxwell G <[email protected]>

* Update docs/docsite/rst/porting_guides/porting_guide_core_2.19.rst

Co-authored-by: Maxwell G <[email protected]>

* Update docs/docsite/rst/porting_guides/porting_guide_core_2.19.rst

Co-authored-by: Maxwell G <[email protected]>

* Update docs/docsite/rst/porting_guides/porting_guide_core_2.19.rst

Co-authored-by: Maxwell G <[email protected]>

* Refresh DT porting guide for 2.19.0b1
* misc reorder, wordsmith
* address review feedback

* Apply suggestions from code review

Update capitalization and quoting.

Co-authored-by: Sandra McCann <[email protected]>

* Apply suggestions from code review

Co-authored-by: Sandra McCann <[email protected]>

* Apply suggestions from code review

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Co-authored-by: Matt Clay <[email protected]>
Co-authored-by: Maxwell G <[email protected]>
Co-authored-by: Sandra McCann <[email protected]>

Author: 4 people