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/mattn/go-isatty/isatty_others.go

@@ -0,0 +1,15 @@
+// +build appengine js nacl
+
+package isatty
+
+// IsTerminal returns true if the file descriptor is terminal which
+// is always false on js and appengine classic which is a sandboxed PaaS.
+func IsTerminal(fd uintptr) bool {
+	return false
+}
+
+// IsCygwinTerminal() return true if the file descriptor is a cygwin or msys2
+// terminal. This is also always false on this environment.
+func IsCygwinTerminal(fd uintptr) bool {
+	return false
+}