Create an option to build docs without executing notebooks

[jaladh-singhal]

Currently, whenever docs are build, the notebooks which are marked to be executed by nbsphinx make build time very long - since each of them runs simulation model. This is fine for production but for development this becomes really annoying.

So there must be some option or flag while running make html or python -m sphinx build to explicitly disable notebooks' execution by nbsphinx on run-time.

Based on my very brief search, nbsphinx doesn't provide any such option for execute control during run-time but only for conf.py and individual notebook's metadata. But I believe, there should be a way to implement this, by adding some if-else logic in conf.py for nbsphinx execute setting which listens to flag specified to build command or something like that.

[epassaro]

The default way to execute cells while rendering notebooks with nbsphinx is to leave all cells blank. If some cell is already executed then the notebook is not executed.

I understand the TARDIS documentation relies on notebook metadata to always execute the notebook and ignore the above method. Using this method and running once the Quickstart guide should be enough to build the documentation more quickly.

I don't know about a fancier way to do this.

[epassaro]

Closed by #1615