Move to katex.org (#1680)

* Change links to katex.org

* Change http to https

* Remove baseUrl hacks

* Fix OpenGraph image link

* Fix KaTeX path update script

docs/support_table.md

@@ -6,7 +6,7 @@ This is a list of TeX functions, sorted alphabetically. This list includes funct
 
 If you know the shape of a character, but not its name, [Detexify](http://detexify.kirelabs.org/classify.html) can help.
 
-{@stylesheet: katex.min.css}
+<link rel="stylesheet" href="/static/katex.min.css"/>
 <style>
 table tr,
 table td {
@@ -446,7 +446,7 @@ table td {
 |\hookleftarrow|$\hookleftarrow$||
 |\hookrightarrow|$\hookrightarrow$||
 |\hphantom|$a\hphantom{bc}d$|`a\hphantom{bc}d`|
-|\href|$\href{https://khan.github.io/KaTeX/}{\KaTeX}$|`\href{https://khan.github.io/KaTeX/}{\KaTeX}`|
+|\href|$\href{https://katex.org/}{\KaTeX}$|`\href{https://katex.org/}{\KaTeX}`|
 |\hskip|$w\hskip1em i\hskip2em d$|`w\hskip1em i\hskip2em d`|
 |\hslash|$\hslash$||
 |\hspace|$s\hspace7ex k$|`s\hspace7ex k`|
@@ -1078,7 +1078,7 @@ table td {
 |\upsilon|$\upsilon$||
 |\upuparrows|$\upuparrows$||
 |\urcorner|$\urcorner$||
-|\url|$\footnotesize\url{https://khan.github.io/KaTeX/}$|`\url{https://khan.github.io/KaTeX/}`|
+|\url|$\footnotesize\url{https://katex.org/}$|`\url{https://katex.org/}`|
 |\utilde|$\utilde{AB}$|`\utilde{AB}`|
 
 ## V