Update Hand Solo rules to 0.16

* [x] Overview - change credits to wealth
* [x] Outline of game structure - flesh out full structure - encounters until year end
* [x] A game turn - explain encounters / space cards?
* [x] Year end - explain fees, retirement, forced retirement, advance year
* [x] Starport - card anatomy
* [x] Contact - card anatomy
* [x] Starport renown - explain flipping
* [x] Explain your ship, development note that almost all of it is unused except cargo hold size and number of cargo holds, and fees
* [x] Example of price calculation
* [x] Buying commodities - remove redundant paragraph
* [x] Selling - add cargo hold size calculation
* [x] Discarding cargo example - when encountering a contact
* [x] Deliver on starports is discard rather than sell
* [x] Errata: Fuel is valuable
* [x] Errata: no fine on merchant contracts

Author: scaires