Add nested kbd element styles for actual keys or inputs
text transformation added

Transform text in components with text capitalization classes.
Color Contrast for panel heading

related to #13686
fix variables in panels.less
fix #13220 Scrollspy generates wrong offsets for a page-- recalculate offsets if `scrollheight` changes
Merge pull request #13783 from twbs/fat-13220

fix #13220
docs callout for #13219
words
grunt
Merge pull request #13687 from smmoosavi/patch-1

Color Contrast for panel heading
grunt
Merge pull request #13671 from 04818419/text-transformation

text transformation added
grunt
fixes #13356: clarify use of clearfix on parents
fix grammar in new callout
Merge pull request #13351 from Cecchi/nested-kbd

Add nested kbd element styles for actual keys or inputs
grunt
Follow-up to #13671; improves consistency of text with previous examples

Also fixes a small indentation error.
Merge pull request #13789 from hnrch02/follow-up-to-13671

Follow-up to #13671; improves consistency of text with previous examples