README.md: add headline

rsc · rsc · commit 20be20937449 · 2017-08-10T20:05:52.000-04:00
diff --git a/README.md b/README.md
@@ -1,3 +1,5 @@
+# rsc.io/getopt
+
 [For full package documentation, see [https://godoc.org/rsc.io/getopt](https://godoc.org/rsc.io/getopt).]
 
     package getopt // import "rsc.io/getopt"

Original file line number	Diff line number	Diff line change
`@@ -1,3 +1,5 @@`
	`1`	`+# rsc.io/getopt`
	`2`	`+`
`1`	`3`	`[For full package documentation, see [https://godoc.org/rsc.io/getopt](https://godoc.org/rsc.io/getopt).]`
`2`	`4`
`3`	`5`	`package getopt // import "rsc.io/getopt"`