don't know how to use get_ops_in_block based on documentation

[sneak]

DEBU[0001] Response: {"jsonrpc":"2.0","error":{"code":-32003,"message":"Assert Exception:_account_history_api: account_history_api_plugin not enabled.","data":{"code":10,"name":"assert_exception","message":"Assert Exception","stack":[{"context":{"level":"error","file":"condenser_api.cpp","line":756,"method":"get_ops_in_block","hostname":"","timestamp":"2018-11-03T14:49:54"},"format":"_account_history_api: account_history_api_plugin not enabled.","data":{}}]}},"id":"1"}

After doing a self-build of 75300af (master as of then) to work around #3130, I am getting the above error when calling condenser_api.get_ops_in_block.

This is after running a steemd based on the documentation in the README, e.g.:

docker run \
    --env USE_WAY_TOO_MUCH_RAM=1 \
    --env USE_FULL_WEB_NODE=1 \
    -d \
    -p 2001:2001 \
    -p 8090:8090 \
    --name steemd-full \
    --restart unless-stopped \
    steemit/steem:selfbuild

Either the README needs an update, or the startup scripts that enable the appropriate plugins do.

(I assume I need to edit the config file, or set some other environment variables, or grok the startup scripts... but that's not the point. The point is that when I run steemd per the documentation, the api calls in the other documentation don't work.)

Perhaps a list of API calls, including the specific method for running a steemd that supports them, is in order? I'm not sure what the optimal fix is here.

[sneak]

Note that after digging through steemd.run to learn that I need IS_AH_NODE=1 to support condenser_api.get_ops_in_block, after using that, steemd crashes per #3142 so I can't actually seem to run a node that supports get_ops_in_block regardless of whether the documentation is adequate or not. :/