IBX-9147: Symbol attribute type described in Developer Documentation

[julitafalcondusza]

Question	Answer
JIRA Ticket	(https://issues.ibexa.co/browse/IBX-9147)
Versions	4.6+

Symbol attribute type described in Developer Documentation

Preview:

• https://ez-systems-developer-documentation--2525.com.readthedocs.build/en/2525/pim/symbol_attribute_type/
• https://ez-systems-developer-documentation--2525.com.readthedocs.build/en/2525/search/criteria_reference/product_search_criteria/#product-search-criteria
• https://ez-systems-developer-documentation--2525.com.readthedocs.build/en/2525/search/criteria_reference/symbolattribute_criterion/

Checklist

• [ ] Text renders correctly
• [ ] Text has been checked with vale
• [ ] Description metadata is up to date
• [ ] Redirects cover removed/moved pages
• [ ] Code samples are working
• [ ] PHP code samples have been fixed with PHP CS fixer
• [ ] Added link to this PR in relevant JIRA ticket or code PR

[adamwojs]

I cannot provide you with the PostgreSQL schema, we will need someone from the backend team for that.

I will take care of it.

[github-actions[bot]]

Preview of modified files

Preview of modified Markdown:

• docs/ibexa_products/editions.md
• docs/pim/attributes/symbol_attribute_type.md
• docs/search/criteria_reference/product_search_criteria.md
• docs/search/criteria_reference/symbolattribute_criterion.md

[mnocon]

Another thing which I forgot about: please add the new LTS update to the table of LTS updates (https://github.com/ibexa/documentation-developer/blob/4.6/docs/ibexa_products/editions.md#lts-updates)