Change portal network image to table

Author: corwintines

public/content/developers/docs/networking-layer/portal-network/index.md

@@ -59,7 +59,10 @@ The benefits of this network design are:
 
 The diagram below shows the functions of existing clients that can be delivered by the Portal Network, enabling users to access these functions on very low-resource devices.
 
-![portal network table](portal-network-table2.png)
+### The Portal Networks
+| Beacon light client | State network | Transaction gossip | History network |
+| ------------------- | ------------- | ------------------ | --------------- |
+| <ul><li>Beacon chain light</li><li>Protocol data</li></ul> | <ul><li>Account and contract storage</li></ul> | <ul><li>Lightweight mempool</li></ul> | <ul><li>Headers</li><li>Block bodies</li><li>Receipts</li></ul> |
 
 ## Client diversity by default {#client-diversity-as-default}