move example inline where possible

The markdown and repo list examples are pretty simple and can easily be
moved to be inline samples so that they render as part of the packages
godocs.  This helps make them more visible even if they won't run in the
browser.  The basic auth example requires interacting with the user, so
leaving it where it is.  Future examples should be included inline
whenever possible.

Author: willnorris

examples/markdown/main.go

@@ -46,6 +46,20 @@ func TestMarkdown(t *testing.T) {
 	}
 }
 
+func ExampleClient_Markdown() {
+	client := NewClient(nil)
+
+	input := "# heading #\n\nLink to issue #1"
+	opt := &MarkdownOptions{Mode: "gfm", Context: "google/go-github"}
+
+	output, _, err := client.Markdown(input, opt)
+	if err != nil {
+		fmt.Println(err)
+	}
+
+	fmt.Println(output)
+}
+
 func TestListEmojis(t *testing.T) {
 	setup()
 	defer teardown()

examples/repos/main.go

@@ -67,6 +67,20 @@ func TestRepositoriesService_List_invalidUser(t *testing.T) {
 	testURLParseError(t, err)
 }
 
+func ExampleRepositoriesService_List() {
+	client := NewClient(nil)
+
+	user := "willnorris"
+	opt := &RepositoryListOptions{Type: "owner", Sort: "updated", Direction: "desc"}
+
+	repos, _, err := client.Repositories.List(user, opt)
+	if err != nil {
+		fmt.Println(err)
+	}
+
+	fmt.Printf("Recently updated repositories by %q: %v", user, Stringify(repos))
+}
+
 func TestRepositoriesService_ListByOrg(t *testing.T) {
 	setup()
 	defer teardown()