Merge branch 'tonyford-master-patch-14020' into 'master'

Update README.md

See merge request tonyford/p2p-fairexchange!1

README.md

 # P2P-FairExchange
 
-Smart and simple exchange managed by git issue tracking system.
\ No newline at end of file
+Smart and simple exchange managed by git issue tracking system.
+
+### Hierachy
+
+| Layer |  | specification |
+|:---:|:---:| --- |
+| 1 | Country | [ISO2](https://www.countrycode.org/) |
+| 2 | Category | |
+| 3 | Need/Level | |
+
+
+### Categories
+