Use an inc for the SemanticUI notice, move under titles

docs/source/_inc/_semanticui-deprecation.md

@@ -0,0 +1,6 @@
+```{deprecated} Volto 18
+Semantic UI development and maintenance has sputtered since 2018.
+The Volto Team made the decision to move forward in a sustainable direction.
+Plone 7 will use a different theming approach, based on the [`@plone/components`](https://www.npmjs.com/package/@plone/components)—which in turn is based on [React Aria Components](https://react-spectrum.adobe.com/react-aria/components.html)—and [`@plone/theming`](https://github.com/plone/volto/tree/main/packages/theming) packages.
+Using Semantic UI theming for your project or add-on is deprecated from Volto 18 onward, and will be removed in Plone 7.
+```

docs/source/contributing/version-policy.md

@@ -96,7 +96,7 @@ We recommend using the current LTS version.
 
 ## Supported web browsers
 
-```{include} /_inc/_install-browser-reqs-volto.md
+```{include} ../../_inc/_install-browser-reqs-volto.md
 ```
 
 

docs/source/theming/about-semantic.md

@@ -9,11 +9,7 @@ myst:
 
 # About Semantic UI
 
-```{deprecated} Volto 18
-Semantic UI development and maintenance has sputtered since 2018.
-The Volto Team made the decision to move forward in a sustainable direction.
-Plone 7 will use a different theming approach, based on the [`@plone/components`](https://www.npmjs.com/package/@plone/components)—which in turn is based on [React Aria Components](https://react-spectrum.adobe.com/react-aria/components.html)—and [`@plone/theming`](https://github.com/plone/volto/tree/main/packages/theming) packages.
-Using Semantic UI theming for your project or add-on is deprecated from Volto 18 onward, and will be removed in Plone 7.
+```{include} /_inc/_semanticui-deprecation.md
 ```
 
 Volto uses [Semantic UI](https://semantic-ui.com/) and

docs/source/theming/custom-styling.md

@@ -7,15 +7,13 @@ myst:
     "keywords": "Volto, Plone, frontend, React, Custom, Styling, Semantic UI, LESS, Pastanaga"
 ---
 
-```{deprecated} Volto 18
-Using SemanticUI theming for your project or add-on is deprecated from Volto 18 on and will be removed from Plone 7.
-Plone 7 will use another theming approach, based on `@plone/components` and `@plone/theming` packages.
-```
-
 # Custom Styling
 
 ## Semantic UI
 
+```{include} /_inc/_semanticui-deprecation.md
+```
+
 For styling our website in Volto we use Semantic UI. It uses LESS as
 the underlying technology. By default Volto uses the Pastanaga theme but any
 theme can be used. A theme has the following folder structure:

docs/source/theming/index.md

@@ -11,9 +11,7 @@ myst:
 
 This section of the documentation describes theming in Volto.
 
-```{deprecated} Volto 18
-Using SemanticUI theming for your project or add-on is deprecated from Volto 18 on and will be removed from Plone 7.
-Plone 7 will use another theming approach, based on `@plone/components` and `@plone/theming` packages.
+```{include} /_inc/_semanticui-deprecation.md
 ```
 
 ## Conceptual guides

docs/source/theming/semanticui-theming.md

@@ -7,13 +7,11 @@ myst:
     "keywords": "Volto, Plone, frontend, React, Semantic UI, Theming"
 ---
 
-```{deprecated} Volto 18
-Using SemanticUI theming for your project or add-on is deprecated from Volto 18 on and will be removed from Plone 7.
-Plone 7 will use another theming approach, based on `@plone/components` and `@plone/theming` packages.
-```
-
 # Semantic UI Theming
 
+```{include} /_inc/_semanticui-deprecation.md
+```
+
 As we hinted previously, Semantic UI theming happens in several stages using several layers of inheritance.
 Let's discover each of these layers.
 

docs/source/theming/theming-a-base-theme.md

@@ -7,11 +7,6 @@ myst:
     "keywords": "Volto, Plone, frontend, React, themes, Volto Light Theme"
 ---
 
-```{deprecated} Volto 18
-Using SemanticUI theming for your project or add-on is deprecated from Volto 18 on and will be removed from Plone 7.
-Plone 7 will use another theming approach, based on `@plone/components` and `@plone/theming` packages.
-```
-
 # Customize a base theme
 
 You can customize a base theme for your add-on.

docs/source/theming/theming-engine.md

@@ -7,13 +7,11 @@ myst:
     "keywords": "Volto, Plone, frontend, React, theming, engine, LESS"
 ---
 
-```{deprecated} Volto 18
-Using SemanticUI theming for your project or add-on is deprecated from Volto 18 on and will be removed from Plone 7.
-Plone 7 will use another theming approach, based on `@plone/components` and `@plone/theming` packages.
-```
-
 # How does the theming engine work?
 
+```{include} /_inc/_semanticui-deprecation.md
+```
+
 It basically uses heavily the LESS precompiler language features. No code is involved (which is good).
 
 ## `theme.config`

docs/source/theming/theming-strategy.md

@@ -7,13 +7,11 @@ myst:
     "keywords": "Volto, Plone, frontend, React, Theming, Strategy"
 ---
 
-```{deprecated} Volto 18
-Using SemanticUI theming for your project or add-on is deprecated from Volto 18 on and will be removed from Plone 7.
-Plone 7 will use another theming approach, based on `@plone/components` and `@plone/theming` packages.
-```
-
 # Theming Strategy
 
+```{include} /_inc/_semanticui-deprecation.md
+```
+
 One approaches the theming of a Volto site usually with a predefined mockup or
 design from a design agency or an UX/UI designer in the form of Sketch files
 (a common design and prototyping tool), a series of photoshop or PDFs with the