v4.1 (#11)

- Add `Json` module to return JSON strings and write JSON as it's read to a `PipeWriter`
- Add `docfx`-based documentation to allow how-to docs and API docs to be generated on the same site

Reviewed-on: #11

.gitignore

@@ -400,3 +400,7 @@ FodyWeavers.xsd
 
 # Test run files
 src/*-tests.txt
+
+# Documentation builds and intermediate files
+_site/
+api/