Add online help for addEmbeddableBadgeConfig Pipeline step (#279)

Online help text is copied from the help page of the plugin.

There is much to be improved in the help page of the plugin and in the
Pipeline help.  The Pipeline help would benefit from a better example
with multiple configurations that each shows its own status.

src/main/resources/org/jenkinsci/plugins/badge/dsl/AddEmbeddableBadgeConfigStep/help-animatedOverlayColor.html

@@ -0,0 +1,7 @@
+You can override the color using the following valid color values:
+
+<ul>
+	<li>one of the values: red, brightgreen, green, yellowgreen, yellow, orange, lightgrey, blue</li>
+	<li>a valid hexadecimal HTML RGB color without the hashtag (e.g. FFAABB).</li>
+	<li>any valid <a href="https://www.december.com/html/spec/colorsvg.html">SVG color name</a></li>
+</ul>

src/main/resources/org/jenkinsci/plugins/badge/dsl/AddEmbeddableBadgeConfigStep/help-color.html

@@ -0,0 +1,7 @@
+You can override the color using the following valid color values:
+
+<ul>
+	<li>one of the values: red, brightgreen, green, yellowgreen, yellow, orange, lightgrey, blue</li>
+	<li>a valid hexadecimal HTML RGB color without the hashtag (e.g. FFAABB).</li>
+	<li>any valid <a href="https://www.december.com/html/spec/colorsvg.html">SVG color name</a></li>
+</ul>

src/main/resources/org/jenkinsci/plugins/badge/dsl/AddEmbeddableBadgeConfigStep/help-id.html

@@ -0,0 +1,3 @@
+The identifier that will be assigned to this embeddable build status configuration.
+The identifier is passed as the value of <code>config</code> in the embeddable build status URL parameter.
+For example, if the identifier value was <code>win32build</code> then the URL parameter would be <code>config=win32build</code>.

src/main/resources/org/jenkinsci/plugins/badge/dsl/AddEmbeddableBadgeConfigStep/help-link.html

@@ -0,0 +1 @@
+The link that will be opened when the embeddable build status badge is clicked.

src/main/resources/org/jenkinsci/plugins/badge/dsl/AddEmbeddableBadgeConfigStep/help-status.html

@@ -0,0 +1 @@
+Text that describes the build status, usually the result of the build.

src/main/resources/org/jenkinsci/plugins/badge/dsl/AddEmbeddableBadgeConfigStep/help-subject.html

@@ -0,0 +1,2 @@
+The text placed on the left side of the embeddable build status.
+The subject is "build" by default.

src/main/resources/org/jenkinsci/plugins/badge/dsl/AddEmbeddableBadgeConfigStep/help.html

@@ -0,0 +1,8 @@
+<p>
+Additional embeddable build status configurations can be created for a Jenkins Pipeline.
+Those embeddable build status configurations can be displayed in the same locations as the default embeddable build status configuration.
+For example, if a Pipeline defined a build status configuration named <code>win32build</code>, that configuration can be accessed by appending <code>config=win32build</code> as one of the embeddable build status URL parameters.
+</p>
+<p>
+Refer to the <a href="https://plugins.jenkins.io/embeddable-build-status/#plugin-content-pipeline-dsl">Embeddable build status</a> documentation for more details.
+</p>