Feat: Add epilog after help text

Similar to the Description at the top of the
help text an Epilog is added at the bottom.

Resolves #189

1 files changed, 32 insertions, 0 deletions

diff --git a/README.md b/README.md
index 7f1fdca..f105b17 100644
--- a/README.md
+++ b/README.md
@@ -462,6 +462,9 @@ Options:
 
 ### Description strings
 
+A descriptive message can be added at the top of the help text by implementing
+a `Description` function that returns a string.
+
 ```go
 type args struct {
 	Foo string
@@ -487,6 +490,35 @@ Options:
   --help, -h             display this help and exit
 ```
 
+Similarly an epilogue can be added at the end of the help text by implementing
+the `Epilogue` function.
+
+```go
+type args struct {
+	Foo string
+}
+
+func (args) Epilogue() string {
+	return "For more information visit github.com/alexflint/go-arg"
+}
+
+func main() {
+	var args args
+	arg.MustParse(&args)
+}
+```
+
+```shell
+$ ./example -h
+Usage: example [--foo FOO]
+
+Options:
+  --foo FOO
+  --help, -h             display this help and exit
+
+For more information visit github.com/alexflint/go-arg
+```
+
 ### Subcommands
 
 *Introduced in version 1.1.0*