Update: namespace crash course (#27662)

* Update: namespace crash course

* Apply suggestions from code review

Co-authored-by: Hamish Willee <hamishwillee@gmail.com>

* xml example

* Update files/en-us/web/svg/namespaces_crash_course/index.md

* Update files/en-us/web/svg/namespaces_crash_course/index.md

Co-authored-by: Onkar Ruikar <87750369+OnkarRuikar@users.noreply.github.com>

* Update files/en-us/web/svg/namespaces_crash_course/index.md

Co-authored-by: Onkar Ruikar <87750369+OnkarRuikar@users.noreply.github.com>

* Update files/en-us/web/svg/namespaces_crash_course/index.md

Co-authored-by: Onkar Ruikar <87750369+OnkarRuikar@users.noreply.github.com>

* Update files/en-us/web/svg/namespaces_crash_course/index.md

Co-authored-by: Joshua Chen <sidachen2003@gmail.com>

* Update files/en-us/web/svg/namespaces_crash_course/index.md

Co-authored-by: Joshua Chen <sidachen2003@gmail.com>

* Apply suggestions from code review

Co-authored-by: Joshua Chen <sidachen2003@gmail.com>

---------

Co-authored-by: Hamish Willee <hamishwillee@gmail.com>
Co-authored-by: Onkar Ruikar <87750369+OnkarRuikar@users.noreply.github.com>
Co-authored-by: Joshua Chen <sidachen2003@gmail.com>