Add a lot of documentation

bind_complete.go

@@ -6,8 +6,11 @@ import (
 
 type BindComplete struct{}
 
+// Backend identifies this message as sendable by the PostgreSQL backend.
 func (*BindComplete) Backend() {}
 
+// Decode decodes src into dst. src must contain the complete message with the exception of the initial 1 byte message
+// type identifier and 4 byte message length.
 func (dst *BindComplete) Decode(src []byte) error {
 	if len(src) != 0 {
 		return &invalidMessageLenErr{messageType: "BindComplete", expectedLen: 0, actualLen: len(src)}
@@ -16,10 +19,12 @@ func (dst *BindComplete) Decode(src []byte) error {
 	return nil
 }
 
+// Encode encodes src into dst. dst will include the 1 byte message type identifier and the 4 byte message length.
 func (src *BindComplete) Encode(dst []byte) []byte {
 	return append(dst, '2', 0, 0, 0, 4)
 }
 
+// MarshalJSON implements encoding/json.Marshaler.
 func (src *BindComplete) MarshalJSON() ([]byte, error) {
 	return json.Marshal(struct {
 		Type string