add DAGs to main readme

README.md

@@ -10,9 +10,23 @@ MetaSnk is a modularized Snakemake workflow for the analysis of metagenomic data
 
 ### Modules:
  - [rawQC](README_rawQC.md)
+
+ <div style="text-align:center">
+   <img src="./images/rawQC_dag.png"  width="130" height="250" />
+ </div>
+
  - [preQC](README_preQC.md)
+
+ <div style="text-align:center">
+   <img src="./images/preQC_dag.png"  width="350" height="500" />
+ </div>
+
  - [PhlAnProf](README_phlanprof.md)
 
+ <div style="text-align:center">
+   <img src="./images/PhlAnProf_dag.png"  width="400" height="800" />
+ </div>
+
 ### Authors
 
 * Monica R. Ticlla (@mticllacc)
@@ -115,7 +129,7 @@ Configure the workflow according to your needs via editing the file `config.yaml
   ```
   - The **OUT_DIR** is the directory where MetaSnk will save the outputs of the
   workflow under the following structure:
-  
+
   ```
     $OUT_DIR
     ├── dataset_test_1