updates markdown parsing to reduce allocations in the same way as the plain text formatter (#2252)

internal/text/markdown.go

@@ -21,6 +21,7 @@ import (
 	"bytes"
 	"context"
 
+	"codeberg.org/gruf/go-byteutil"
 	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
 	"github.com/superseriousbusiness/gotosocial/internal/log"
 	"github.com/yuin/goldmark"
@@ -65,17 +66,21 @@ func (f *Formatter) FromMarkdown(
 		),
 	)
 
+	// Convert input string to bytes
+	// without performing any allocs.
+	bInput := byteutil.S2B(input)
+
 	// Parse input into HTML.
 	var htmlBytes bytes.Buffer
 	if err := md.Convert(
-		[]byte(input),
+		bInput,
 		&htmlBytes,
 	); err != nil {
 		log.Errorf(ctx, "error formatting markdown input to HTML: %s", err)
 	}
 
 	// Clean and shrink HTML.
-	result.HTML = htmlBytes.String()
+	result.HTML = byteutil.B2S(htmlBytes.Bytes())
 	result.HTML = SanitizeToHTML(result.HTML)
 	result.HTML = MinifyHTML(result.HTML)