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/gallery.sh

@@ -0,0 +1,20 @@
+#!/bin/bash
+
+for style in ./styles/*.json; do
+    echo "Generating screenshot for ${style}"
+    filename="`basename -s .json ${style}`.png"
+
+    light=""
+    if [[ $style == *"light"* ]]; then
+        light="-l"
+    fi
+
+    # take screenshot
+    ./termshot ${light} -o ./styles/gallery/ -f "$filename" glow -s ${style}
+
+    # add border
+    convert -bordercolor black -border 16x16 "./styles/gallery/$filename" "./styles/gallery/$filename"
+
+    # optimize filesize
+    pngcrush -ow "./styles/gallery/$filename"
+done