Capitalize type names so variables can use them

Capitalize type names so variables can use them

The go-code skill now asks for type names with a capital letter and for
all other package-level names in lower case. A lower-case type name
clashes with an import, such as a log type with the log package, and
with local variables that have the name of their type, such as a memory
variable of a memory type. A capital letter keeps both names free.