Inviting Readers Web team per JdlRobson's request.
==== Problem statement:
* Less variable names
* Don't follow the [[ https://phabricator.wikimedia.org/source/wikimedia-ui-base/browse/master/wikimedia-ui-base.less$194 | pattern of WMUI ]]
* Include implementation details: `sans` / `serif`
* Lack semantic details: `base` (body) / `heading`
* Lack of documentation (comments) about the fonts, the research and reasoning behind those.
==== Solution:
1. Replace `@font-family-sans` -> `@font-family-base` for main page content.3 renames:
* In variables.less `@font-family-base` is defined with the value of `@font-family-sans`,1. which is not changed`@font-family-sans` -> `@font-family-base` -- Body content.
* Replace2. `@font-family-serif` -> `@font-family-heading` for h -- Headings.
* In variables.less3. `@font-family-sans--fallback` -> `@font-family-heading` is defined with the value of `@font-family-serif`--fallback` -- Headings for languages Japanese, which is not changedHebrew, just commented.Korean (T73240,T65817,T65843,T65844,T65827)
* This makes a step forward from WMUI, renaming `@font-family-heading-main` -> `@font-family-heading`
* Reason: there are no different heading kinds named in any skin, nor is that expected.
* This the only change that concerns WMUI in patch [[ https://gerrit.wikimedia.org/r/c/wikimedia-ui-base/+/573046 | 573046 ]]
* Copy the comment for each individual font from the proposed WMUI documentation from patch [[ https://gerrit.wikimedia.org/r/c/wikimedia-ui-base/+/573609 | 573609 ]]
Please share your feedback, agreement, disagreement. This patch has been in the works for many weeks. The font comments were strongly influenced by and benefitted a lot from @Jdlrobson's [[ https://gerrit.wikimedia.org/r/c/mediawiki/skins/MinervaNeue/+/573065#message-8d9d30a1be4235ac474cec76b110149cf69e004f | awesome and practical help ]] in the related patch for MinervaNeue.
Patch for review: [[ https://gerrit.wikimedia.org/r/c/mediawiki/skins/Vector/+/570638 | 570638 ]]