GH-2333 readme file specifically for website editing (#2394)

site/README.md

@@ -0,0 +1,25 @@
+# Eclipse RDF4J Hugo website 
+
+This directory contains the source of the official RDF4J project website at
+https://rdf4j.org/, including all technical documentation.
+
+The RDF4J project website is generated using the [Hugo](https://gohugo.io/) static website generator, and uses the [Eclipse Foundation Solstice Theme](https://github.com/EclipseFdn/hugo-solstice-theme).
+
+The solstice theme is included as a git submodule. To check out a local copy, run 
+
+    git submodule update --init --recursive
+
+You should only need to do this once after cloning the rdf4j repository.
+
+Most website content can be found in the `content/` directory, as (Goldmark)
+Markdown files. We allow inclusion of raw html as well, but please use this
+sparingly: we prefer use of markdown to make future maintenance as easy as
+possible.
+
+To generate a site locally for easy editing/debugging, simply execute
+
+    hugo server --disableFastRender
+
+A local copy of the website will be accessible on http://localhost:1313/. You
+can edit the content using your text editor of choice, the hugo server will
+automatically re-render the pages you edit as you go.