show asciidoc counters does not show all the counters available
Since show asciidoc counters only iterates through the allocated rate_ctr/stat_item groups it does not necessarily show all the counters that can be available.
For example the sgsn only creates (and reports) bssgp:bss_ctx counters if there is actually a bssgp configured in the sgsn. While you could argue that this is just a misconfiguration the issue remains with counters allocated for each mm or pdp context. As long as no phones are GMM attached the command show asciidoc counters does not know about any statistics for mm or pdp context.
We could add commands to add the rate_ctr_group_desc ans osmo_stat_item_group_desc to another list which keeps track of available counters and traverse that for show asciidoc stats as we don't need the actual allocations for counter values that the *_group_alloc() functions do. Group and counter description needed for documentation are all available from the *_group_desc structs.
This would mean that we need to register every counter group independently from the *_group_alloc() calls happening right now, so the documentation knows about them - but as a side effect we could also have a function to allocate a rate_ctr/stat_item group by name (instead of struct pointer). Not sure how useful that would be.