docs: add/update some godoc comments

internal/cpu/opcodes.go

@@ -1,5 +1,7 @@
 package cpu
 
+// op represents an operation. It includes the name of the op, it's 8 bit hexidecimal
+// opcode, how many bytes it occupies (it's size), as well as it's addressing mode.
 type op struct {
 	name           string
 	opcode         uint8
@@ -16,6 +18,8 @@ func newOp(name string, opcode, size uint8, addressingMode addressingMode) op {
 	}
 }
 
+// opcodes represent all of the Apple 1 opcodes available. Each 8 bit opcode is mapped to a corresponding
+// "op" which is just a struct holding metadata about the operation.
 var opcodes = map[uint8]op{
 	// BRK Force Break
 	// addressing    assembler    opc  bytes  cyles

pkg/appleone/appleone.go

@@ -2,12 +2,12 @@ package appleone
 
 import "github.com/bradford-hamilton/apple-1/internal/cpu"
 
-// Appleone TODO docs
+// Appleone represents our virtual Apple 1 computer
 type Appleone struct {
 	cpu *cpu.Mos6502
 }
 
-// New TODO: docs
+// New returns a pointer to an initialized Appleone with a brand spankin new CPU
 func New() *Appleone {
 	return &Appleone{cpu: cpu.New()}
 }