Update docs README w/ steps on generating config props

Signed-off-by: Chris Bono <chris.bono@gmail.com>

Author: onobc

build-docs.sh

@@ -0,0 +1,3 @@
+#!/bin/bash
+
+./mvnw -pl spring-grpc-docs process-resources antora -P docs

spring-grpc-docs/README.md

@@ -8,13 +8,13 @@ The top level README and CONTRIBUTING guidleines documentation are generated fro
 The Spring gRPC configuration properties are automatically documented as follows:
 
 1. This module contains a Java class (`org.springframework.grpc.internal.ConfigurationPropertiesAsciidocGenerator`) that is compiled when the module is built.
-1. This class is then used during the Maven `package` phase to generate an asciidoc page containing each of the configuration properties.
+1. This class is then used during the Maven `process-resources` phase in the `docs` profile to generate an asciidoc page containing each of the configuration properties.
 1. The asciidoc is then included in the Antora reference documentation.
 
 ## Antora Site
 
 To build the Antora site locally run the following command from the project root directory:
 ```
-./mvnw -pl spring-grpc-docs antora
+./mvnw -pl spring-grpc-docs process-resources antora -P docs
 ```
 You can then view the output by opening `spring-grpc-docs/target/antora/site/index.html`.