minimise README churn

Signed-off-by: rmlearney-digicatapult <robert.learney@digicatapult.org.uk>

Author: rmlearney-digicatapult

README.md

@@ -95,7 +95,7 @@ The built-in cache uses a `Map` and does not have an automatic TTL, so entries d
 Enable the built-in cache by passing `cache: true` to the constructor:
 
 ```js
-const resolver = new Resolver({
+const resolver = new DIDResolver({
   ethr,
   web
 }, {
@@ -145,7 +145,7 @@ const customCache: DIDCache = async (parsed, resolve, options) => {
   return doc
 }
 
-const resolver = new Resolver({
+const resolver = new DIDResolver({
   ethr,
   web
 }, {