chore: deprecate template create command in favor of template push (#11390)

cli/cliui/deprecation.go

@@ -0,0 +1,21 @@
+package cliui
+
+import (
+	"fmt"
+
+	"github.com/coder/coder/v2/cli/clibase"
+	"github.com/coder/pretty"
+)
+
+func DeprecationWarning(message string) clibase.MiddlewareFunc {
+	return func(next clibase.HandlerFunc) clibase.HandlerFunc {
+		return func(i *clibase.Invocation) error {
+			_, _ = fmt.Fprintln(i.Stdout, "\n"+pretty.Sprint(DefaultStyles.Wrap,
+				pretty.Sprint(
+					DefaultStyles.Warn,
+					"DEPRECATION WARNING: This command will be removed in a future release."+"\n"+message+"\n"),
+			))
+			return next(i)
+		}
+	}
+}