Update did_how_to_use.md

Swapped one of the examples.

docs/w3c_did/did_how_to_use.md

@@ -13,6 +13,6 @@ To get started, enter the URL representing a DID, and click on **Resolve DID**.
 [https://dev.uniresolver.io/](https://dev.uniresolver.io/) and [https://godiddy.com/app/resolve](https://godiddy.com/app/resolve) provide a number of examples for a variety of DID methods.
 Here are a few to get you started!
 
->`did:cheqd:testnet:55dbc8bf-fba3-4117-855c-1e0dc1d3bb47`\
+>`did:cheqd:mainnet:Ps1ysXP2Ae6GBfxNhNQNKN`\
 >`did:ebsi:zkC6cUFUs3FiRp2xedNwih2`\
 >`did:indy:indicio:demo:KKyAeG7woJMV6MhhAREVKp`