doc: start with the core documentation for the slicing process

wiki/Core.md

@@ -1,5 +1,35 @@
 ***This wiki page is currently under construction***
 
-In-Depth Explanation of *flowR*
+This wiki page should give the in-depth explanation of the inner workings of *flowR*. To avoid duplication it may often contain links to the internal code documentation (located here: <https://code-inspect.github.io/flowr/doc/>).
+
+<!-- TOC -->
+- [The Slicing Process](#the-slicing-process)
+  - [The Steps](#the-steps)
+    - [Step 1: Parsing the R Code](#step-1-parsing-the-r-code)
+    - [Step 2: Normalizing the AST](#step-2-normalizing-the-ast)
+    - [Step 3: Dataflow Analysis on the Normalized AST](#step-3-dataflow-analysis-on-the-normalized-ast)
+    - [Step 4: Slicing on the Dataflow Graph](#step-4-slicing-on-the-dataflow-graph)
+    - [Step 5: Reconstruct the R Code](#step-5-reconstruct-the-r-code)
+<!-- TOC -->
+
+## The Slicing Process
+
+All slicing steps are defined in [src/core/steps.ts](https://github.com/Code-Inspect/flowr/blob/main/src/core/steps.ts). This is the core definition of all steps executed by the [`SteppingSlicer`](https://github.com/Code-Inspect/flowr/blob/main/src/core/slicer.ts) (refer to the [interface](https://github.com/Code-Inspect/flowr/wiki/Interface) wiki page for more information on how to use the stepping slicer).
+
+If you want to execute a single step (for whatever reason) there are two ways to do that:
+
+1. Use the `SteppingSlicer` with its `SteppingSlicer::hasNextStep` and `SteppingSlicer::nextStep` methods. This is the recommended way as it executes all required steps before your step of interest as well.
+2. Calling `executeSingleSubStep(<step name>, <remaining arguments>)` which only executes the given step (it is up to you to provide the correct arguments).
+
+### The Steps
+
+#### Step 1: Parsing the R Code
+
+#### Step 2: Normalizing the AST
+
+#### Step 3: Dataflow Analysis on the Normalized AST
+
+#### Step 4: Slicing on the Dataflow Graph
+
+#### Step 5: Reconstruct the R Code
 
-See the internal documentation: <https://code-inspect.github.io/flowr/doc/>