README: Remove Infura mention

There are now multiple options for ethereum node providers, and discussing that is outside the scope of the README>

README.md

@@ -19,10 +19,7 @@ To build and run this project you need to have the following installed on your s
 - PostgreSQL – [PostgreSQL Downloads](https://www.postgresql.org/download/)
 - IPFS – [Installing IPFS](https://docs.ipfs.io/install/)
 
-For Ethereum network data, you can either run a local node or use Infura.io:
-
-- Local node – [Installing and running Ethereum node](https://ethereum.gitbooks.io/frontier-guide/content/getting_a_client.html)
-- Infura infra – [Infura.io](https://infura.io/)
+For Ethereum network data, you can either run your own Ethereum node or use an Ethereum node provider of your choice.
 
 ### Running a Local Graph Node
 
@@ -46,14 +43,12 @@ Once you have all the dependencies set up, you can run the following:
 ```
 cargo run -p graph-node --release -- \
   --postgres-url postgresql://USERNAME[:PASSWORD]@localhost:5432/graph-node \
-  --ethereum-rpc mainnet:https://mainnet.infura.io/v3/[PROJECT_ID] \
+  --ethereum-rpc [URL] \
   --ipfs 127.0.0.1:5001
 ```
 
 Try your OS username as `USERNAME` and `PASSWORD`. The password might be optional. It depends on your setup.
 
-If you're using Infura you should [sign up](https://infura.io/register) to get a PROJECT_ID, it's free.
-
 This will also spin up a GraphiQL interface at `http://127.0.0.1:8000/`.
 
 6.  With this ENS example, to get the subgraph working locally run: