Deprecated filters in our docs should list valid alternatives.

[Poitrin]

Is your feature request related to a problem? Please describe.
Deprecated filters in our docs can be marked deprecated, but have no information about valid replacements.
Example: hex_to_rgba → color_to_rgb, color_modify
Therefore, theme-check still has data/shopify_liquid/deprecated_filters.json, which does contain this information.

Describe the solution you'd like
Each deprecated filter in our docs lists valid alternatives.

Describe alternatives you've considered
Alternative would be to keep the JSON file.