Access reorg

[asteiker]

• Finalized basic cloud data access how-to using ICESat-2 example, simplifying to small # of lines of code and explanation.
• Updated table of contents based on hackday reorg discussion
• Did not delete existing access how-to's but removed them from quarto.yml

[andypbarrett]

The rendered quarto pages look good but there are some merge conflicts. Would @asteiker normally fix these? I can also try to fix.