fix(docs): font size issue

[kuzhelov]

Repro steps:

• open root docs page (https://stardust-ui.github.io/react/)
• switch to Radio component page (https://stardust-ui.github.io/react/components/radio)

Expected result

• default font size remains to be 14px
  

Actual result

• default font size is switched on 10px
  

Cause:

The issue is caused by the following tree being rendered:

<Provider theme={mergeThemes(teams,
  siteVariables: {
    ...
   htmlFontSize: '14px'
 })}
 ...
  <ComponentExample>
     <Provider theme={mergeThemes(teams, newTheme)}>
     ...
     </Provider>
   </ComponentExample>
} />

As we might see, when component example is rendered, teams theme as applied once again - with all its static styles that invalidate htmlFontSize: 14px override and set htmlFontSize to 10px, the value defined by teams theme.

Provided fix eliminates specifying theme for individual example, as we would rather like to apply theme changes for all examples altogether.

Broader issue to fix

It is a very dangerous phenomena related to the fact that theme applied to subtree of components might change look of the overall page - with global CSS selectors being used in its static styles. More than that, this problem is very hard to diagnose, and for some situations I might imagine that it will be even hard to spot. I would propose to apply mechanisms of scoping static CSS selectors to the subtree theme as applied for (by default), with opened possibility to explicitly allow global CSS for Provider:

{ /*global CSS selectors are allowed, so that theme could change overall page's look */ }
<Provider theme={teams} allowGlobalCss>  
  ...
  { /* static CSS styles provided will be scoped to Provider's subtree only */ }
  <Provider theme={someTheme}> 
     ...
  </Provider>
...
</Provider>

[levithomason]

I don't think we should advertise doc changes here, only library changes. Thoughts on keeping the changelog specific to the library itself?

[levithomason]

Cruft entry here.

[levithomason]

Some cleanup is due here.

[levithomason]

Agree on the broader issue. @davezuko and I also discussed this similar issue. There is also the converse case that something rendered down the tree might need to add statics or font faces in order to work.