Lua: add new module pandoc.highlighting.
          
            #6939
        
      | Job | Run time | 
|---|---|
| 11m 9s | |
| 8m 46s | |
| 27m 48s | |
| 6m 17s | |
| 18m 26s | |
| 21m 28s | |
| 2m 56s | |
| 9m 42s | |
| 18m 10s | |
| 9m 34s | |
| 2h 14m 16s | 
pandoc.highlighting.
          
            #6939
        
| Job | Run time | 
|---|---|
| 11m 9s | |
| 8m 46s | |
| 27m 48s | |
| 6m 17s | |
| 18m 26s | |
| 21m 28s | |
| 2m 56s | |
| 9m 42s | |
| 18m 10s | |
| 9m 34s | |
| 2h 14m 16s |