godoc: moves sealed type notes to the top and backfills where missing (#1397)

wazero uses interfaces even when they aren't intended to be implemented
by users. We relied on documentation, to suggest what is implementable,
and in some cases documented correctly types that weren't for
implementation.

However, we didn't add that boilerplate to all types, and we also forgot
to recently when it was discussed a week or two ago. This finishes the
job by boilerplating all types that aren't for implementation. This also
orders to the top when it already existed.

Later, we can choose to enforce by type as well, we didn't know how to
do that before. Basically before we just casted to our internal types,
which would stop accidental implementation for things except people
using the types for wrapping purposes.

Signed-off-by: Adrian Cole <adrian@tetrate.io>

runtime.go

@@ -25,9 +25,9 @@ import (
 //
 // # Notes
 //
-//   - Closing this closes any CompiledModule or Module it instantiated.
 //   - This is an interface for decoupling, not third-party implementations.
 //     All implementations are in wazero.
+//   - Closing this closes any CompiledModule or Module it instantiated.
 type Runtime interface {
 	// Instantiate instantiates a module from the WebAssembly binary (%.wasm)
 	// with default configuration.