Added drone build

.drone.yml

@@ -0,0 +1,15 @@
+kind: pipeline
+type: docker
+name: default
+
+steps:
+  - name: build
+    image: lyx:latest
+    pull: if-not-exists
+    commands:
+    - lyx --export pdf4 lrftubes.lyx
+
+      #  - name: gitea_release
+      #    image: plugins/gitea-release
+      #    api_key:
+