Enable writing plain text straight to output

It's only used in a single place and should probably be refactored away,
but this workaround is OK for now.

html.go

@@ -187,6 +187,10 @@ func (r *Html) CopyWrites(processor func()) []byte {
 	return output.Bytes()
 }
 
+func (r *Html) Write(b []byte) (int, error) {
+	return r.w.Write(b)
+}
+
 func (r *Html) GetResult() []byte {
 	return r.w.output.Bytes()
 }

inline.go

@@ -748,7 +748,7 @@ func autoLink(p *parser, data []byte, offset int) int {
 
 	anchorStr := anchorRe.Find(data[anchorStart:])
 	if anchorStr != nil {
-		out.Write(anchorStr[offsetFromAnchor:]) // XXX: write in parser?
+		p.r.Write(anchorStr[offsetFromAnchor:]) // XXX: write in parser?
 		return len(anchorStr) - offsetFromAnchor
 	}
 

latex.go

@@ -60,6 +60,10 @@ func (r *Latex) CopyWrites(processor func()) []byte {
 	return output.Bytes()
 }
 
+func (r *Latex) Write(b []byte) (int, error) {
+	return r.w.Write(b)
+}
+
 func (r *Latex) GetResult() []byte {
 	return r.w.output.Bytes()
 }

markdown.go

@@ -204,6 +204,7 @@ type Renderer interface {
 	GetFlags() HtmlFlags
 	CaptureWrites(processor func()) []byte
 	CopyWrites(processor func()) []byte
+	Write(b []byte) (int, error)
 	GetResult() []byte
 }