remove duplicate attributes that are handled by playbook

docs/modules/ROOT/pages/build-preview-ui.adoc

@@ -1,8 +1,4 @@
 = Build a UI Project for Local Preview
-// Settings:
-:idprefix:
-:idseparator: -
-:experimental:
 
 == Build Preview Site
 

docs/modules/ROOT/pages/development-workflow.adoc

@@ -1,7 +1,4 @@
 = UI Development Workflow
-// Settings:
-:idprefix:
-:idseparator: -
 
 // This section provides information about some of the UI files you'll be modifying and how to prepare and submit those changes.
 

docs/modules/ROOT/pages/index.adoc

@@ -1,23 +1,20 @@
 = Antora Default UI
 // Settings:
-:idprefix:
-:idseparator: -
-:experimental:
 :hide-uri-scheme:
-// URIs:
-:uri-antora: https://antora.org
-:uri-repo: https://gitlab.com/antora/antora-ui-default
-:uri-preview: https://antora.gitlab.io/antora-ui-default
-:uri-hbs: http://handlebarsjs.com
-:uri-gulp: http://gulpjs.com
-:uri-npm: https://npmjs.com
-:uri-node: https://nodejs.org
-:uri-nvm: https://github.com/creationix/nvm
-:uri-nvm-install: {uri-nvm}#installation
-:uri-git: https://git-scm.com
-:uri-git-dl: {uri-git}/downloads
-
-This project produces the {uri-preview}[default UI bundle] for documentation sites generated with {uri-antora}[Antora].
+// URLs:
+:url-antora: https://antora.org
+:url-repo: https://gitlab.com/antora/antora-ui-default
+:url-preview: https://antora.gitlab.io/antora-ui-default
+:url-hbs: https://handlebarsjs.com
+:url-gulp: https://gulpjs.com
+:url-npm: https://npmjs.com
+:url-node: https://nodejs.org
+:url-nvm: https://github.com/creationix/nvm
+:url-nvm-install: {url-nvm}#installation
+:url-git: https://git-scm.com
+:url-git-dl: {url-git}/downloads
+
+This project produces the {url-preview}[default UI bundle] for documentation sites generated with {url-antora}[Antora].
 It contains the UI assets (page templates, CSS, JavaScript, images, etc.) and a Gulp build script.
 The build can be used to preview the UI locally (featuring live updates), or to package it for consumption by the Antora site generator.
 
@@ -44,16 +41,16 @@ The Antora UI consists of the following file types that are used to structure an
 To understand how the UI works, let's begin by surveying the primary technologies used by the UI.
 
 Handlebars (file extension: `.hbs`)::
-{uri-hbs}[Handlebars] is a "`logic-less`" templating engine used to create HTML from template files.
+{url-hbs}[Handlebars] is a "`logic-less`" templating engine used to create HTML from template files.
 Templates contain placeholders (i.e., mustache expressions like `+{{{page.title}}}+`) into which content is injected from a model.
 They also accommodate simple logic expressions for repeating content or including it conditionally (e.g., `+{{#each navigation}}+`) as well as partials (e.g., `+{{> header}}+`).
 
 Gulp (script file: [.path]_gulpfile.js/index.js_)::
-{uri-gulp}[Gulp] is a build tool for JavaScript projects.
+{url-gulp}[Gulp] is a build tool for JavaScript projects.
 It configures a collection of tasks that can be used to perform automated tasks such as compiling files, running a preview server, or publishing a release.
 
 npm (command: `npm`)::
-npm manages software packages (i.e., software dependencies) that it downloads from {uri-npm}.
+npm manages software packages (i.e., software dependencies) that it downloads from {url-npm}.
 Software this project uses includes libraries that handle compilation as well as shared assets such as font files that are distributed as npm packages.
 npm is part of Node.js.
 

docs/modules/ROOT/pages/prerequisites.adoc

@@ -1,8 +1,5 @@
 = UI Development Prerequisites
-// Settings:
-:idprefix:
-:idseparator: -
-// URIs:
+// URLs:
 :url-nvm: https://github.com/creationix/nvm
 :url-node: https://nodejs.org
 :url-gulp: http://gulpjs.com

docs/modules/ROOT/pages/set-up-project.adoc

@@ -1,19 +1,15 @@
 = Set up a UI Project
-// Settings:
-:idprefix:
-:idseparator: -
-// URIs:
-:uri-project: https://gitlab.com/antora/antora-ui-default.git
+:url-project: https://gitlab.com/antora/antora-ui-default.git
 
 Before you can start working on the UI, you need to grab the sources and initialize the project.
-The sources can be {uri-project}[Antora's default UI] or an existing UI project structured to work with Antora.
+The sources can be {url-project}[Antora's default UI] or an existing UI project structured to work with Antora.
 
 == Fetch the Default UI project
 
 To start, clone the default UI project using git:
 
 [subs=attributes+]
- $ git clone {uri-project} &&
+ $ git clone {url-project} &&
    cd "`basename $_`"
 
 The example above clones Antora's default UI project and then switches to the project folder on your filesystem.

docs/modules/ROOT/pages/stylesheets.adoc

@@ -1,7 +1,4 @@
 = Work with the CSS Stylesheets
-// Settings:
-:idprefix:
-:idseparator: -
 
 The stylesheets are written in CSS.
 These stylesheets utilize CSS variables to keep the CSS DRY and easy to customize.

docs/modules/ROOT/pages/templates.adoc

@@ -1,7 +1,4 @@
 = Work with the Handlebars Templates
-// Settings:
-:idprefix:
-:idseparator: -
 
 Antora combines the Handlebars templates with the converted AsciiDoc content and other UI model data to make the pages in the site.
 These "`logic-less`" templates are mostly HTML with some special mustache tags sprinkled in where content should be inserted.