fix: provide examples and clarification to use rust code blocks (#277)

Author: PLeVasseur

.github/ISSUE_TEMPLATE/CODING-GUIDELINE.yml

@@ -155,22 +155,24 @@ body:
     attributes:
       label: Non-Compliant Example - Code
       description: |
-        Code example showcasing the unintended or consequential behavior. Non-normative.
+        Code example showcasing the unintended or consequential behavior. Non-normative. Please wrap your code in a fenced code block with the `rust` language specifier.
 
         **Hidden lines:** If your code needs `use` statements, a `fn main()` wrapper, or other boilerplate to compile, but you don't want them shown in the documentation, prefix those lines with `# ` (hash + space). These lines will be compiled but hidden in the rendered docs.
 
         Example with hidden lines:
-        ```
+        ```rust
         # use std::mem::MaybeUninit;
         # fn main() {
         let x: u32 = unsafe { MaybeUninit::uninit().assume_init() }; // UB
         # }
         ```
       placeholder: |
+        ```rust
         # use std::collections::HashMap;
         # fn main() {
         let map = HashMap::new();
         # }
+        ```
     validations:
       required: true
   - type: textarea
@@ -186,21 +188,23 @@ body:
     attributes:
       label: Compliant Example - Code
       description: |
-        Code example showcasing we avoid unintended or consequential behavior by following the Coding Guideline.
+        Code example showcasing we avoid unintended or consequential behavior by following the Coding Guideline. Please wrap your code in a fenced code block with the `rust` language specifier.
 
         **Hidden lines:** If your code needs `use` statements, a `fn main()` wrapper, or other boilerplate to compile, but you don't want them shown in the documentation, prefix those lines with `# ` (hash + space). These lines will be compiled but hidden in the rendered docs.
 
         Example with hidden lines:
-        ```
+        ```rust
         # use std::collections::HashMap;
         # fn main() {
         let mut map = HashMap::new();
         map.insert("key", "value"); // Compliant usage
         # }
         ```
       placeholder: |
+        ```rust
         # fn main() {
         let safe_value = 42u32; // Properly initialized
         # }
+        ```
     validations:
       required: true