README update

README.md

@@ -1,6 +1,6 @@
 # CommaFeed
 
-Google Reader inspired self-hosted RSS reader, based on Dropwizard and React/TypeScript.
+Google Reader inspired self-hosted RSS reader, based on Quarkus and React/TypeScript.
 
 ![preview](https://user-images.githubusercontent.com/1256795/184886828-1973f148-58a9-4c6d-9587-ee5e5d3cc2cb.png)
 
@@ -16,6 +16,12 @@ Google Reader inspired self-hosted RSS reader, based on Dropwizard and React/Typ
 - OPML import/export
 - REST API and a Fever-compatible API for native mobile apps
 - [Browser extension](https://github.com/Athou/commafeed-browser-extension)
+- Compiles to native code for very fast startup and low memory usage
+- Supports 4 databases
+    - H2 (embedded database)
+    - PostgreSQL
+    - MySQL
+    - MariaDB
 
 ## Deployment
 
@@ -33,28 +39,31 @@ PikaPods shares 20% of the revenue back to CommaFeed.
 
 [![PikaPods](https://www.pikapods.com/static/run-button.svg)](https://www.pikapods.com/pods?run=commafeed)
 
-### Download precompiled package
+### Download a precompiled package
 
-    mkdir commafeed && cd commafeed
-    wget https://github.com/Athou/commafeed/releases/latest/download/commafeed.jar
-    wget https://github.com/Athou/commafeed/releases/latest/download/config.yml.example -O config.yml
-    java -Djava.net.preferIPv4Stack=true -jar commafeed.jar server config.yml
+Go to the [release page](https://github.com/Athou/commafeed/releases) and download the latest version for your operating
+system and database of choice.
 
-The server will listen on http://localhost:8082. The default
-user is `admin` and the default password is `admin`.
+There are two types of packages:
+
+- The `linux` and `windows` packages are compiled natively and contain an executable that can be run directly.
+- The `jvm` package contains a Java `.jar` file that works on all platforms and is started with
+  `java -jar quarkus-run.jar`.
+
+If available for your operating system, the native package is recommended because it has a faster startup time and lower
+memory usage.
 
 ### Build from sources
 
-    git clone https://github.com/Athou/commafeed.git
-    cd commafeed
-    ./mvnw clean package
-    cp commafeed-server/config.yml.example config.yml
-    java -Djava.net.preferIPv4Stack=true -jar commafeed-server/target/commafeed.jar server config.yml
+    ./mvnw clean package -P<database> [-DskipTests] [-Pnative]
 
-The server will listen on http://localhost:8082. The default
-user is `admin` and the default password is `admin`.
+- `<database>` can be one of `h2`, `postgresql`, `mysql` or `mariadb`.
+- `-DskipTests` is optional but recommended because tests require a Docker environment to run against a real database.
+- `-Pnative` compiles the application to native code. This requires GraalVM to be installed (GRAALVM_HOME environment
+  variable
+  pointing to a GraalVM installation).
 
-### Memory management
+### Memory management (`jvm` package only)
 
 The Java Virtual Machine (JVM) is rather greedy by default and will not release unused memory to the
 operating system. This is because acquiring memory from the operating system is a relatively expensive operation.
@@ -86,6 +95,37 @@ IBM provides precompiled binaries for OpenJ9
 named [Semeru](https://developer.ibm.com/languages/java/semeru-runtimes/downloads/).
 This is the JVM used in the [Docker image](https://github.com/Athou/commafeed/blob/master/Dockerfile).
 
+## Configuration
+
+There are multiple ways to configure CommaFeed:
+
+- a properties file in `config/application.properties` (kebab-case)
+- Command line arguments prefixed with `-D` (kebab-case)
+- Environment variables (UPPER_CASE)
+- an .env file in the working directory (UPPER_CASE)
+
+The properties file is recommended because CommaFeed will be able to warn about invalid properties and typos.
+
+CommaFeed only requires 3 properties to be configured:
+
+- `quarkus.datasource.username`
+- `quarkus.datasource.password`
+- `quarkus.datasource.jdbc-url`
+    - H2: `jdbc:h2:/commafeed/data/db;DEFRAG_ALWAYS=TRUE`
+    - PostgreSQL: `jdbc:postgresql://localhost:5432/commafeed`
+    - MySQL:
+      `jdbc:mysql://localhost/commafeed?autoReconnect=true&failOverReadOnly=false&maxReconnects=20&rewriteBatchedStatements=true&timezone=UTC`
+    - MariaDB:
+      `jdbc:mariadb://localhost/commafeed?autoReconnect=true&failOverReadOnly=false&maxReconnects=20&rewriteBatchedStatements=true&timezone=UTC`
+
+All
+other [CommaFeed settings](https://github.com/Athou/commafeed/blob/master/commafeed-server/src/main/java/com/commafeed/CommaFeedConfiguration.java)
+are optional and have sensible default values.
+See [here](https://quarkus.io/guides/all-config) for more information about Quarkus configuration.
+
+When started the server will listen on http://localhost:8082.
+The default user is `admin` and the default password is `admin`.
+
 ## Translation
 
 Files for internationalization are
@@ -108,7 +148,7 @@ two-letters [ISO-639-1 language code](http://en.wikipedia.org/wiki/List_of_ISO_6
 
 - Open `commafeed-server` in your preferred Java IDE.
     - CommaFeed uses Lombok, you need the Lombok plugin for your IDE.
-- Start `CommaFeedApplication.java` in debug mode with `server config.dev.yml` as arguments
+- run `mvn quarkus:dev`
 
 ### Frontend