Docs: Add diagram of processing pipeline

makefile

@@ -4,9 +4,13 @@ help: makefile
 
 
 .PHONY: build
-build: cli-spec.json
+build: cli-spec.json processing-pipeline.svg
 
 
 cli-spec.json: oclis-contract.ncl oclis.ncl
 	echo '(import "oclis-contract.ncl") & (import "oclis.ncl")' \
 	| nickel export --format json > $@
+
+
+processing-pipeline.svg: processing-pipeline.dot
+	dot -T svg -o $@ $<

processing-pipeline.dot

@@ -0,0 +1,55 @@
+digraph ProcessingPipeline {
+  graph [size="6"];
+  splines=ortho;
+
+  edge[fontname="Sans-Serif"]
+  node[style=filled, fillcolor=gray90]
+
+  node[fontname="Monospace"]
+  tokens [label="[Token]", shape="parallelogram"]
+  args [label="[Argument]", shape="parallelogram"]
+
+  node[fontname="Sans-Serif"]
+  in [label="CLI Input", shape="parallelogram"]
+  refine [label="Refine", shape="rectangle"]
+  exec [label="Execute", shape="rectangle"]
+  out [label="Output", shape="parallelogram"]
+  clispec [
+    shape="cylinder",
+    label=<
+<br/>
+CLI Spec<br/>
+<br/>
+<font point-size="10">  Provided by the user  </font>
+>
+    ]
+  mapping [
+    shape="cylinder",
+    label=<
+<br/>
+Argument<br/>
+↓<br/>
+Function<br/>
+<br/>
+<font point-size="10">  Provided by the user  </font>
+>
+    ]
+
+  in -> tokens [label="  Tokenize  "]
+  tokens -> refine
+  clispec -> refine
+  refine -> args
+  args -> exec
+  mapping -> exec
+  exec -> out
+
+  // Align clispec node to the right of refine and on the same level
+  refine -> clispec [style=invis]
+  clispec -> tokens [style=invis]
+  subgraph { rank=same; refine; clispec; }
+
+  // Align mapping node to the right of exec and on the same level
+  exec -> mapping [style=invis]
+  mapping -> args [style=invis]
+  subgraph { rank=same; exec; mapping; }
+}

readme.md

@@ -19,6 +19,13 @@ But fear not, Oclis is here to help you out!
 4. Done 🎉
 
 
+## How It Works
+
+### Processing Pipeline
+
+![Processing Pipeline](./processing-pipeline.svg)
+
+
 ## Related
 
 ### Tools