fs: Prevent invalid directory links

A file with a name like "gemini:example" would previously result in the
following invalid link:

    => gemini:example gemini:example

Fix by prepending a "./" before each filename, so that the resulting
link looks like:

    => ./gemini:example gemini:example

README.md

@@ -6,7 +6,7 @@ Package gemini implements the [Gemini protocol](https://gemini.circumlunar.space
 in Go. It provides an API similar to that of net/http to facilitate the
 development of Gemini clients and servers.
 
-Compatible with version v0.14.3 of the Gemini specification.
+Compatible with version v0.16.0 of the Gemini specification.
 
 ## Usage
 

doc.go

@@ -30,7 +30,7 @@ Servers should be configured with certificates:
 	server.GetCertificate = certificates.Get
 
 Mux is a Gemini request multiplexer.
-Mux can handle requests for multiple hosts and schemes.
+Mux can handle requests for multiple hosts and paths.
 
 	mux := &gemini.Mux{}
 	mux.HandleFunc("example.com", func(ctx context.Context, w gemini.ResponseWriter, r *gemini.Request) {
@@ -39,8 +39,8 @@ Mux can handle requests for multiple hosts and schemes.
 	mux.HandleFunc("example.org/about.gmi", func(ctx context.Context, w gemini.ResponseWriter, r *gemini.Request) {
 		fmt.Fprint(w, "About example.org")
 	})
-	mux.HandleFunc("http://example.net", func(ctx context.Context, w gemini.ResponseWriter, r *gemini.Request) {
-		fmt.Fprint(w, "Proxied content from http://example.net")
+	mux.HandleFunc("/images/", func(ctx context.Context, w gemini.ResponseWriter, r *gemini.Request) {
+		w.WriteHeader(gemini.StatusGone, "Gone forever")
 	})
 	server.Handler = mux
 

fs.go

@@ -169,7 +169,7 @@ func dirList(w ResponseWriter, f fs.File) {
 		}
 		link := LineLink{
 			Name: name,
-			URL:  (&url.URL{Path: name}).EscapedPath(),
+			URL:  "./" + url.PathEscape(name),
 		}
 		fmt.Fprintln(w, link.String())
 	}

text.go

@@ -125,8 +125,8 @@ func ParseLines(r io.Reader, handler func(Line)) error {
 				name = strings.TrimLeft(name, spacetab)
 				line = LineLink{url, name}
 			}
-		} else if strings.HasPrefix(text, "*") {
-			text = text[1:]
+		} else if strings.HasPrefix(text, "* ") {
+			text = text[2:]
 			text = strings.TrimLeft(text, spacetab)
 			line = LineListItem(text)
 		} else if strings.HasPrefix(text, "###") {