docs: make rules documentation more consistent

.github/ISSUE_TEMPLATE/rule_proposal.md

@@ -12,11 +12,11 @@ assignees:
 - **Severity: (warning|error)**
 - **Fixable: (yes|no)**
 
-## Problematic code example
+## Problematic Code Example
 
 Provide an example of code that would trigger this rule.
 
-## Correct code example
+## Correct Code Example
 
 Provide an example of the code that would pass the rule.
 

docs/rules/__TEMPLATE__.md

@@ -8,15 +8,15 @@ Short rule description.
 - **Severity:**
 - **Fixable:**
 
-## Problematic code example
+## Problematic Code Example
 
-```yml
+```yaml
 
 ```
 
-## Correct code example
+## Correct Code Example
 
-```yml
+```yaml
 
 ```
 
@@ -36,4 +36,4 @@ This rule was introduced in [v1.0.0](https://github.com/zavoloklom/docker-compos
 
 ## References
 
-Links
+- [Reference link](https://example.com)

docs/rules/no-quotes-in-volumes-rule.md

@@ -12,7 +12,7 @@ themselves.
 - **Severity:** info
 - **Fixable:** true
 
-## Problematic code example
+## Problematic Code Example
 
 ```yaml
 services:
@@ -23,7 +23,7 @@ services:
       - "logs:/app/logs"
 ```
 
-## Correct code example
+## Correct Code Example
 
 ```yaml
 services:

docs/rules/no-version-field-rule.md

@@ -9,18 +9,18 @@ the "version" field is removed, promoting consistency and modern practices in Do
 - **Severity:** minor
 - **Fixable:** true
 
-## Problematic code example
+## Problematic Code Example
 
-```yml
+```yaml
 version: '3.8'
 services:
   web:
     image: image
 ```
 
-## Correct code example
+## Correct Code Example
 
-```yml
+```yaml
 services:
   web:
     image: image

docs/rules/require-project-name-field-rule.md

@@ -9,18 +9,18 @@ The "name" field should be present in the Docker Compose file. This rule enforce
 - **Severity:** minor
 - **Fixable:** false
 
-## Problematic code example
+## Problematic Code Example
 
-```yml
+```yaml
 services:
   foo:
     image: image
     command: echo "I'm running ${COMPOSE_PROJECT_NAME}"
 ```
 
-## Correct code example
+## Correct Code Example
 
-```yml
+```yaml
 name: myapp
 
 services:

docs/rules/require-quotes-in-ports-rule.md

@@ -13,7 +13,7 @@ ports themselves. The type of quotes (single or double) can be configured via th
 - **Severity:** minor
 - **Fixable:** true
 
-## Problematic code example
+## Problematic Code Example
 
 ```yaml
 services:
@@ -26,9 +26,10 @@ services:
       - 3000
 ```
 
-## Correct code example (Single Quotes)
+## Correct Code Example
 
 ```yaml
+# Single Quotes
 services:
   foo:
     image: image
@@ -39,9 +40,8 @@ services:
       - '3000'
 ```
 
-## Correct code example (Double Quotes)
-
 ```yaml
+# Double Quotes
 services:
   foo:
     image: image

docs/rules/service-dependencies-alphabetical-order-rule.md

@@ -12,7 +12,7 @@ internal content.
 - **Severity:** info
 - **Fixable:** true
 
-## Problematic code example
+## Problematic Code Example
 
 ```yaml
 services:
@@ -35,7 +35,7 @@ services:
         restart: true
 ```
 
-## Correct code example
+## Correct Code Example
 
 ```yaml
 services:

docs/rules/service-keys-order-rule.md

@@ -12,7 +12,7 @@ without altering their internal content.
 - **Severity:** minor
 - **Fixable:** true
 
-## Problematic code example
+## Problematic Code Example
 
 ```yaml
 services:
@@ -27,7 +27,7 @@ services:
       - "8080:8080"
 ```
 
-## Correct code example
+## Correct Code Example
 
 ```yaml
 services:

docs/rules/services-alphabetical-order-rule.md

@@ -7,14 +7,14 @@ This rule is fixable. The linter can automatically reorder services in alphabeti
 internal structure or content.
 
 - **Rule Name:** services-alphabetical-order
-- **Type:** error
+- **Type:** warning
 - **Category:** style
 - **Severity:** minor
 - **Fixable:** true
 
-## Problematic code example
+## Problematic Code Example
 
-```yml
+```yaml
 services:
   d_service:
     image: image
@@ -26,9 +26,9 @@ services:
     image: image
 ```
 
-## Correct code example
+## Correct Code Example
 
-```yml
+```yaml
 services:
   a_service:
     image: image

docs/rules/top-level-properties-order-rule.md

@@ -7,12 +7,12 @@ This rule is fixable. The linter can automatically reorder the top-level propert
 without altering their internal content.
 
 - **Rule Name:** top-level-properties-order
-- **Type:** error
+- **Type:** warning
 - **Category:** style
 - **Severity:** major
 - **Fixable:** true
 
-## Problematic code example
+## Problematic Code Example
 
 ```yaml
 services:
@@ -26,7 +26,7 @@ networks:
     driver: bridge
 ```
 
-## Correct code example
+## Correct Code Example
 
 ```yaml
 x-alpha: alpha