Fix a table of contents of maps

Signed-off-by: Masanori Misono <[email protected]>

docs/reference_guide.md

@@ -45,16 +45,18 @@ This guide is incomplete. If something feels missing, check the bcc and kernel s
  - [10. BPF_DEVMAP](#10-bpf_devmap)
  - [11. BPF_CPUMAP](#11-bpf_cpumap)
  - [12. BPF_XSKMAP](#12-bpf_xskmap)
- - [13. map.lookup()](#13-maplookup)
- - [14. map.lookup_or_try_init()](#14-maplookup_or_try_init)
- - [15. map.delete()](#15-mapdelete)
- - [16. map.update()](#16-mapupdate)
- - [17. map.insert()](#17-mapinsert)
- - [18. map.increment()](#18-mapincrement)
- - [19. map.get_stackid()](#19-mapget_stackid)
- - [20. map.perf_read()](#20-mapperf_read)
- - [21. map.call()](#21-mapcall)
- - [22. map.redirect_map()](#22-mapredirect_map)
+ - [13. BPF_ARRAY_OF_MAPS](#13-bpf_array_of_maps)
+ - [14. BPF_HASH_OF_MAPS](#14-bpf_hash_of_maps)
+ - [15. map.lookup()](#15-maplookup)
+ - [16. map.lookup_or_try_init()](#16-maplookup_or_try_init)
+ - [17. map.delete()](#17-mapdelete)
+ - [18. map.update()](#18-mapupdate)
+ - [19. map.insert()](#19-mapinsert)
+ - [20. map.increment()](#20-mapincrement)
+ - [21. map.get_stackid()](#21-mapget_stackid)
+ - [22. map.perf_read()](#22-mapperf_read)
+ - [23. map.call()](#23-mapcall)
+ - [24. map.redirect_map()](#24-mapredirect_map)
  - [Licensing](#licensing)
 
 - [bcc Python](#bcc-python)