Use glamour and termev to render/colorize content (#181)

Merge branch 'master' into use-glamour

select Glamour Theme based on BackgroundColor

Merge branch 'master' into use-glamour

Merge branch 'master' into use-glamour

update termev

update go.mod

label color colorate

use glamour for issue content

Vendor: Add glamour

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: 6543 <6543@obermui.de>
Reviewed-on: https://gitea.com/gitea/tea/pulls/181
Reviewed-by: techknowlogick <techknowlogick@gitea.io>
Reviewed-by: Lunny Xiao <xiaolunwen@gmail.com>

vendor/github.com/charmbracelet/glamour/ansi/image.go

@@ -0,0 +1,39 @@
+package ansi
+
+import (
+	"io"
+)
+
+// An ImageElement is used to render images elements.
+type ImageElement struct {
+	Text    string
+	BaseURL string
+	URL     string
+	Child   ElementRenderer // FIXME
+}
+
+func (e *ImageElement) Render(w io.Writer, ctx RenderContext) error {
+	if len(e.Text) > 0 {
+		el := &BaseElement{
+			Token: e.Text,
+			Style: ctx.options.Styles.ImageText,
+		}
+		err := el.Render(w, ctx)
+		if err != nil {
+			return err
+		}
+	}
+	if len(e.URL) > 0 {
+		el := &BaseElement{
+			Token:  resolveRelativeURL(e.BaseURL, e.URL),
+			Prefix: " ",
+			Style:  ctx.options.Styles.Image,
+		}
+		err := el.Render(w, ctx)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}