Add /about endpoint

handlers/about.go

@@ -0,0 +1,16 @@
+package handlers
+
+import (
+	"net/http"
+
+	"github.com/labstack/echo/v4"
+
+	"git.sr.ht/~cwpearson/replicate-jump-server/config"
+)
+
+func AboutGet(c echo.Context) error {
+	return c.JSON(http.StatusOK, map[string]string{
+		"version":    config.GitSHA(),
+		"build-date": config.BuildDate(),
+	})
+}