Add StripMarkdown option (irc). (#1145)

Enable `StripMarkdown` to strip markdown for irc.

bridge/config/config.go

@@ -136,6 +136,7 @@ type Protocol struct {
 	SkipTLSVerify          bool       // IRC, mattermost
 	SkipVersionCheck       bool       // mattermost
 	StripNick              bool       // all protocols
+	StripMarkdown          bool       // irc
 	SyncTopic              bool       // slack
 	TengoModifyMessage     string     // general
 	Team                   string     // mattermost, keybase

bridge/irc/irc.go

@@ -14,6 +14,7 @@ import (
 	"github.com/42wim/matterbridge/bridge/config"
 	"github.com/42wim/matterbridge/bridge/helper"
 	"github.com/lrstanley/girc"
+	stripmd "github.com/writeas/go-strip-markdown"
 
 	// We need to import the 'data' package as an implicit dependency.
 	// See: https://godoc.org/github.com/paulrosania/go-charset/charset
@@ -156,6 +157,10 @@ func (b *Birc) Send(msg config.Message) (string, error) {
 	}
 
 	var msgLines []string
+	if b.GetBool("StripMarkdown") {
+		msg.Text = stripmd.Strip(msg.Text)
+	}
+
 	if b.GetBool("MessageSplit") {
 		msgLines = helper.GetSubLines(msg.Text, b.MessageLength)
 	} else {