docs: add release document

Author: anonrig

docs/RELEASE.md

@@ -0,0 +1,19 @@
+# Release Document
+
+## Preparation
+
+In order to release a new version of Ada, please update the
+following documents:
+
+- [CmakeLists.txt](../CmakeLists.txt)
+- [Doxygen](../doxygen)
+- [ada-version.h](../include/ada/ada-version.h)
+
+## Release
+
+- Run amalgation script using `./singleheader/amalgamate.py`
+- Create a Github release with following format: `v1.0.0`
+- Upload the following documents to the release
+  - `./singleheader/ada.h`
+  - `./singleheader/ada.cpp`
+  - `./singleheader/singleheader.zip`