Add shiny assistant context

Author: jthomasmock

.github/styles/config/vocabularies/posit-docs/accept.txt

@@ -29,6 +29,7 @@ File Explorer
 Connections Pane
 Positron Pro
 Positron Assistant
+Shiny Assistant
 GitHub Copilot
 Anthropic Claude
 Anthropic Claude Sonnet

assistant.qmd

@@ -109,6 +109,14 @@ Assistant's Chat pane (in the Activity Panel by default) knows about your R and
 
 Code generated by Assistant can be run in the Console, copied to the clipboard, or sent to the Editor via controls attached to code output blocks.
 
+#### Slash commands
+
+Slash commands provide quick access to common tasks without writing long prompts. Start by typing / in the chat box to see available commands. For example, the `/quarto` command converts the current chat conversation into a Quarto document.
+
+#### Chat participants
+
+Chat participants provide specialized knowledge to the Positron Assistant. You can add a chat participant by typing `@` in the Chat pane then the chat participant name. Please reference the [Shiny Assistant](#shiny-assistant) section for more information on the use of a Shiny chat participant.
+
 ### Inline chat
 
 The command _Inline Chat: Editor Inline Chat_ (default keybinding: Cmd + I) will open a mini chat right in the editor. This is very useful for asking questions in context, and also includes a good UX for integrating changes suggested by the model.
@@ -120,6 +128,12 @@ If GitHub Copilot is enabled and the user pauses typing for a few seconds, Posit
 - Make sure you have a [language model provider added](#adding-language-model-providers) for completions.
 - Check the DevTools Console logs to see if there are any errors logged. Run the `Developer: Toggle Developer Tools` command in the Command Palette to open DevTools.
 
+## Shiny Assistant
+
+The Shiny Assistant is a specialized tool available within Positron Assistant that provides context-aware assistance for Shiny applications in Python or R. It can help you with tasks such as generating Shiny UI components, server logic, and reactive expressions.
+
+The Shiny Assistant is available in the chat pane and inline chat once you have enabled Positron Assistant and installed the [Shiny extension](https://open-vsx.org/extension/posit/shiny). Like other chat participants, Shiny Assistant can be invoked by typing `@shiny` in the chat pane or inline chat, followed by your question or request related to Shiny development.
+
 ## Language model provider API keys & authentication
 
 ::: {.callout-tip}