Doc for @AddConfigBlock #8807

[jbescos]

Description

#8807

Documentation

Included in this PR

[tjquinno]

A few changes, please.

[tjquinno]

Please:

1. Change line 110: "Define a new" to "Define additional"

2. Change line 110: "a single configuration key/value." to "one or more configuration key/value pairs."

3. Change line 106: "Define a new" to "Define additional"

   I know line 106 is not part of your changes in this PR but the original "Define a new" could be interpreted to mean "replace" which is not what it does.

4. Add code illustrating @AddConfigBlock to the snippet referenced immediately after the table.

[jbescos]

Thank you for the review. It is done now.

[tjquinno]

Sorry, one more small change request.

[tjquinno]

The example should illustrate what we can do with this annotation that we cannot do with the other...declare multiple settings as in the text you added to the doc.

[jbescos]

The problem is that the helidon/examples/quickstarts/helidon-quickstart-mp only uses one config property, so there is no point to add more.

I cannot create new config properties to inject in the test as a field, because of:
java.lang.RuntimeException: When a class is annotated with @HelidonTest(resetPerTest=true), injection into fields or constructor is not supported, as each test method uses a different CDI container. Field private java.lang.String io.helidon.microprofile.tests.testing.junit5.TestAddConfigBlockProperties.value1 is annotated with @Inject

Basically I need to create a new Snippet to test something like:

@HelidonTest
@AddConfigBlock("""
    some.key1=some.value1
    some.key2=some.value2
""")
class TestAddConfigBlockProperties {

    @Inject
    @ConfigProperty(name = "some.key1")
    private String value1;

    @Inject
    @ConfigProperty(name = "some.key2")
    private String value2;

    @Test
    void testValue() {
        assertThat(value1, is("some.value1"));
        assertThat(value2, is("some.value2"));
    }
}

Do you agree with it?

[jbescos]

I have pushed the change. Just let me know whether you are fine with it.