docs+lnrpc: rename rpc.proto to lightning.proto

To avoid a naming conflict with etcd, we rename our very generic
rpc.proto to lightning.proto to match the service name that's declared
within. This will break many external tutorials and possibly also our
API docs but the change needs to be done eventually.

docs/grpc/javascript.md

@@ -13,16 +13,16 @@ dependencies:
 npm install grpc @grpc/proto-loader --save
 ```
 
-You also need to copy the `lnd` `rpc.proto` file in your project directory (or
-at least somewhere reachable by your Javascript code).
+You also need to copy the `lnd` `lightning.proto` file in your project directory
+(or at least somewhere reachable by your Javascript code).
 
-The `rpc.proto` file is [located in the `lnrpc` directory of the `lnd`
-sources](https://github.com/lightningnetwork/lnd/blob/master/lnrpc/rpc.proto).
+The `lightning.proto` file is [located in the `lnrpc` directory of the `lnd`
+sources](https://github.com/lightningnetwork/lnd/blob/master/lnrpc/lightning.proto).
 
 ### Imports and Client
 
 Every time you work with Javascript gRPC, you will have to import `grpc`, load
-`rpc.proto`, and create a connection to your client like so:
+`lightning.proto`, and create a connection to your client like so:
 
 ```js
 const grpc = require('grpc');
@@ -43,7 +43,7 @@ const loaderOptions = {
   defaults: true,
   oneofs: true
 };
-const packageDefinition = protoLoader.loadSync('rpc.proto', loaderOptions);
+const packageDefinition = protoLoader.loadSync('lightning.proto', loaderOptions);
 
 //  Lnd cert is at ~/.lnd/tls.cert on Linux and
 //  ~/Library/Application Support/Lnd/tls.cert on Mac
@@ -192,7 +192,7 @@ const loaderOptions = {
   defaults: true,
   oneofs: true
 };
-const packageDefinition = protoLoader.loadSync('rpc.proto', loaderOptions);
+const packageDefinition = protoLoader.loadSync('lightning.proto', loaderOptions);
 
 process.env.GRPC_SSL_CIPHER_SUITES = 'HIGH+ECDSA'