Updates package comments

mailcap.go

@@ -1,3 +1,7 @@
+// Package mailcap is a port of the python3 mailcap library to golang and
+// provides developers with the ability to query mimetypes and keys against 
+// the various mailcap files on a system to acquire an appropriate command 
+// to run in order to view, edit, etc a given file of a given mimetype.
 package mailcap
 
 import (
@@ -10,9 +14,22 @@ import (
 	"sort"
 )
 
+// Entry is a map of strings keyed with strings that represents a single
+// mailcap entry. It represents one prgram for one mimetype. An entry can
+// contain options for various keys (test, view, edit, etc).
 type Entry map[string]string
+
+// Fields is a slice of entries that gets used as a part of the Cap type
 type Fields []Entry
+
+// Cap is a map of Fields (itself a slice of Entries) and represents
+// each mimetype and a slice of the various entries (programs) available
+// for that mimetype.
 type Cap	map[string]Fields
+
+// Mailcap is the main struct to interact with. It contains a Cap, as
+// caps, that represents the full mailcap db for the system. It has a 
+// number of receivers to facilitate retrieving a command from a mimetype.
 type Mailcap struct {
 	Caps	Cap
 }