Fix syntax highlighting for generic type

```
const head = <T,>(arr: T[]): T => arr[0]
```

#86

Author: yuezk

after/syntax/jsx_pretty.vim

@@ -36,7 +36,7 @@ syntax region jsxElement
 
 " detect jsx region
 syntax region jsxRegion
-      \ start=+\(\(\_[([,?:=+\-*/<>{}]\|&&\|||\|=>\|\<return\|\<default\|\<await\|\<yield\)\_s*\)\@<=<\_s*\(>\|\z(\(script\)\@!\<[_\$A-Za-z][-:_\.\$0-9A-Za-z]*\>\)\(\_s*\([-+*)\]}&|?]\|/\([/*]\|\_s*>\)\@!\)\)\@!\)+
+      \ start=+\(\(\_[([,?:=+\-*/<>{}]\|&&\|||\|=>\|\<return\|\<default\|\<await\|\<yield\)\_s*\)\@<=<\_s*\(>\|\z(\(script\)\@!\<[_\$A-Za-z][-:_\.\$0-9A-Za-z]*\>\)\(\_s*\([-+*)\]}&|?,]\|/\([/*]\|\_s*>\)\@!\)\)\@!\)+
       \ end=++
       \ contains=jsxElement