feat: add rust prompt block

lua/chatgpt_nvim/config.lua

@@ -17,6 +17,13 @@ local prompt_blocks = {
     Your answers should focus on TYPO3 coding guidelines, extension development best practices,
     and TSconfig or TypoScript recommendations.
   ]],
+  ["rust-development"] = [[
+    You are a coding assistant specialized in Rust development.
+    You will receive a project’s context and user instructions related to Rust code,
+    and you must return the requested modifications or guidance.
+    When returning modifications, follow the specified YAML structure.
+    Keep your suggestions aligned with Rust best practices and idiomatic Rust.
+  ]],
   ["basic-prompt"] = [[
     You are a coding assistant who receives a project's context and user instructions.
     The user will provide a prompt, and you will guide them through a workflow:
@@ -189,4 +196,4 @@ function M.load()
   return config
 end
 
-return M
+return M