Finish initializing.md

docs/docs/getting-started/initializing.md

@@ -1,7 +1,108 @@
 ---
 sidebar_position: 1
-title: Initializing
+title: Initializing the engine
 ---
 
-# Initializing
-## TODO
+# Initializing the engine
+To initialize the sos!engine, simply add this to the initialization code of your application:
+```java
+new Engine();
+```
+
+This is enough to initialize the engine and all installed subsystems. No need to manually initialize them.
+
+## Printing something
+Now you'll probably want to print some log output. Before you try using `System.out#println`,
+`java.util.logging`, Log4J, SLFJ or some other logging library, please don't! The engine
+provides it's own logging implementation and is HIGHLY recommended to be used instead.
+
+There are eight log levels you can use:
+<table>
+    <tr>
+        <th>Level</th>
+        <th>Description</th>
+    </tr>
+    <tr>
+        <th>DIAGNOSTIC</th>
+        <th>Provide detailed information about what is happening</th>
+    </tr>
+    <tr>
+        <th>VERBOSE</th>
+        <th>Additional information that may not be useful</th>
+    </tr>
+    <tr>
+        <th>SILENT_WARNING</th>
+        <th>Warnings that can be ignored or are caused by invalid (API) user input</th>
+    </tr>
+    <tr>
+        <th>INFORMATIONAL</th>
+        <th>Useful information about what is happening</th>
+    </tr>
+    <tr>
+        <th>WARNING</th>
+        <th>Warnings about dangerous or weird behaviour</th>
+    </tr>
+    <tr>
+        <th>ERROR</th>
+        <th>Non-fatal errors</th>
+    </tr>
+    <tr>
+        <th>CRASH</th>
+        <th>Fatal errors which may or may not halt the running program (see below)</th>
+    </tr>
+</table>
+
+Here's an example:
+```java
+Logger.info(new LogIssuer(Main.class), "Hello World!");
+```
+
+Now, what is this `LogIssuer` garbage? It's simple: It describes the class issuing the log call. You can for example pass along information about the data you are handling to easily distinguish instances:
+```java
+class ExampleClass() {
+    @NotNull
+    private String string;
+    
+    public ExampleClass(@NotNull String string) {
+        this.string = string;
+    }
+    
+    public boolean checkForEscapes() {
+        Logger.diag(new LogIssuer(getClass(), string), "Checking for escapes");
+        return string.contains("\\");
+    }
+    
+    public boolean checkIfEmpty() {
+        Logger.diag(new LogIssuer(getClass(), string), "Checking if empty");
+        return string.isEmpty();
+    }
+}
+```
+
+But it's lame to always pass that to every log call you make. For that reason `LoggerInstance` exists.
+Here's the class from before but with `LoggerInstance`:
+```java
+class ExampleClass() {
+    @NotNull
+    private LoggerInstance logger = new LoggerInstance(new LogIssuer(getClass(), string));
+    
+    @NotNull
+    private String string;
+    
+    public ExampleClass(@NotNull String string) {
+        this.string = string;
+    }
+    
+    public boolean checkForEscapes() {
+        logger.diag("Checking for escapes");
+        return string.contains("\\");
+    }
+    
+    public boolean checkIfEmpty() {
+        logger.diag("Checking if empty");
+        return string.isEmpty();
+    }
+}
+```
+
+As you can see, it's much simpler. No need to pass that to every call now!