Make help links configurable

[SylvainCorlay]

No description provided.

[SylvainCorlay]

cc @aburgm

[takluyver]

@minrk do the shimmed .append() etc. methods on config work to add to default values, or only to previously loaded values? If it's not easy to modify the default, maybe we should leave this non-configurable and add an extra attribute for config to add links.

[SylvainCorlay]

@takluyver when you generate the profile, the default values get added to the config file, so it is easy to modify.

[minrk]

Yup, append adds to the default. We've also done extra_foo configurables for clearly defining additional items, rather than modifying the existing list. I could go either way. Whether we want people to be able to replace the defaults should probably determine whether we add config=True to the existing trait vs a dedicated extra_help_links trait for more user-defined links.

[SylvainCorlay]

Yup, append adds to the default. We've also done extra_foo configurables for clearly defining additional items, rather than modifying the existing list. I could go either way. Whether we want people to be able to replace the defaults should probably determine whether we add config=True to the existing trait vs a dedicated extra_help_links trait for more user-defined links.

Do we want to force users to keep the current list of links?

[SylvainCorlay]

Do we want to force users to keep the current list of links?

A possible usecase is the one of someone who does not want to use external links...

[takluyver]

OK, so long as it's easy to add to the defaults, I'm fine with doing it like this.

[minrk]

Do we want to force the current list of links to users?

That's the question! I don't feel the need to force these links to be always-on, so I'm fine with this PR as-is.