Improve Markdown rendering

* Remove paragraphs from output HTML
* Remove mention link wrapper from text (leaving only mention name)

lib/bfhtml/doc.go

@@ -0,0 +1,2 @@
+// Package bfhtml contains an extension to the Blackfriday HTML renderer to disable paragraph tags.
+package bfhtml

lib/bfhtml/html.go

@@ -0,0 +1,34 @@
+// gomuks - A terminal Matrix client written in Go.
+// Copyright (C) 2018 Tulir Asokan
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package bfhtml
+
+import (
+	"io"
+
+	bf "gopkg.in/russross/blackfriday.v2"
+)
+
+type HTMLRenderer struct {
+	*bf.HTMLRenderer
+}
+
+func (r *HTMLRenderer) RenderNode(w io.Writer, node *bf.Node, entering bool) bf.WalkStatus {
+	if node.Type == bf.Paragraph {
+		return bf.GoToNext
+	}
+	return r.HTMLRenderer.RenderNode(w, node, entering)
+}