Add a basic README (#8)

Signed-off-by: Juan Cruz Viotti <[email protected]>

README.markdown

@@ -0,0 +1,57 @@
+Sourcemeta Registry
+===================
+
+A high-performance OEM micro-service to serve collections of JSON Schema over
+HTTP and build a schema registry for your organisation.
+
+Configuration
+-------------
+
+The Sourcemeta Registry requires a configuration file that defines the schema
+collections and pages the instance will serve. See
+[`schemas/configuration.json`](./schemas/configuration.json) for the JSON
+Schema that defines this configuration file format. The format is designed to
+be easy to understand and performant to interact with at runtime.  Here is an
+example:
+
+```json
+{
+  "url": "http://localhost:8000",
+  "port": 8000,
+  "collections": {
+    "example/schemas": {
+      "base": "https://example.com/schemas",
+      "path": "./schemas/example/folder"
+    }
+  }
+}
+```
+
+The `url` property defines the base URL of the instance and will be used for
+reidentifying schemas at runtime, so make sure its correct. The `port` property
+is optional. The `collections` property mounts a given directory of schemas
+into a certain relative path.
+
+Deployment
+----------
+
+We release a small `registry` Docker base image to [GitHub
+Packages](https://github.com/sourcemeta/registry/pkgs/container/registry) that
+you are expected to extend for your own deployment as follows. Replace any `{{
+}}` variable with the values of your choosing:
+
+```docker
+FROM ghcr.io/sourcemeta/registry:{{ version }}
+
+# Copy your configuration file (see previous section) and schema files
+COPY {{ path/to/configuration.json }} /app/configuration.json
+COPY {{ path/to/schemas }} /app/schemas
+
+# Index your schema directory given your configuration
+RUN sourcemeta-registry-index /app/configuration.json /app/index \
+    && rm -rf /app/schemas /app/configuration.json
+
+# Run the registry against your indexed directory
+ENTRYPOINT [ "/usr/bin/sourcemeta-registry-serve" ]
+CMD [ "/app/index" ]
+```