fix notebooks to use full URLs rather than short names

[sbenthall]

Using short names is confusing for people because it assumes the data collection script has been run to function.

[npdoty]

Are we agreed on this? I also prefer using full URLs, but I thought that @davidberra was trying to switch the sample notebooks to shortnames, maybe for ease of use for beginners?

[davidberra]

i dont have a strong opinion on this, so if you all prefer urls i'll stick to that

[sbenthall]

Tied to #501

A lot of the funkiness of how the original BigBang code swaps between URLs, 'short names', etc. is because it was aimed to make Notebook analysis feel lightweight.

It would be easier to do a rewrite if we deprecate more of the notebooks in favor of more systematic/consolidated ways of doing analysis.