Update to Diagrams.net 14.7.4

CHANGELOG.md

@@ -5,6 +5,9 @@
 ### Added
 - Theme of editor can be configured via plugin's settings (#65)
 
+### Changed
+- Update to Diagrams.net 14.7.4
+
 ## [0.1.7] - 2021-04-27
 
 ### Changed

src/webview/README.adoc

@@ -0,0 +1,27 @@
+= Sub-Modules
+
+This is a sub-module pointing to https://github.com/jgraph/drawio.
+
+== Why a submodules
+
+This allows tracking te upstream development in a relatively straightforward way.
+
+== How to update
+
+Run the following commands when you want to update it:
+
+----
+cd src/webview/drawio
+git checkout dev
+cd ..
+git add drawio
+git commit ...
+git push
+----
+
+Run the following commands for all other developers:
+
+----
+git pull
+git submodule update --init
+----