Modify rule S6294: "Log Groups" should be declared explicitly (#4530)

* Modify rule S6294: "Log Groups" should be declared explicitly

* Code review remarks

Co-authored-by: GabinL21 <67428953+GabinL21@users.noreply.github.com>

---------

Co-authored-by: GabinL21 <67428953+GabinL21@users.noreply.github.com>

rules/S6294/cloudformation/rule.adoc

@@ -57,7 +57,7 @@ Resources:
 
 ==== Compliant solution
 
-Example with a `!Ref`:
+Example with a `!Ref` in `LogGroup`:
 
 [source,yaml]
 ----
@@ -76,6 +76,27 @@ Resources:
       RetentionInDays: 30
 ----
 
+Example with a `!Ref` in `AWS::Lambda::Function` (it also works for `AWS::Serverless::Function`):
+
+[source,yaml]
+----
+AWSTemplateFormatVersion: 2010-09-09
+Resources:
+  ExampleFunction:
+    Type: AWS::Lambda::Function
+    Properties:
+      Runtime: nodejs12.x
+      Description: Example of Lambda Function
+      LoggingConfig:
+        LogGroup: !Ref ExampleLogGroup
+
+  ExampleLogGroup:
+    Type: AWS::Logs::LogGroup
+    Properties:
+      LogGroupName: "/aws/lambda/exampleFunction"
+      RetentionInDays: 30
+----
+
 Example with `!Sub`:
 
 [source,yaml]
@@ -95,6 +116,21 @@ Resources:
       RetentionInDays: 30
 ----
 
+Example with `CloudWatchLogs` (it only works for `AWS::CodeBuild::Project`):
+
+[source,yaml]
+----
+AWSTemplateFormatVersion: 2010-09-09
+Resources:
+  CodeBuildProject:
+    Type: AWS::CodeBuild::Project
+    Properties:
+      LogsConfig:
+        CloudWatchLogs:
+          Status: "ENABLED"
+          GroupName: "aws/codeBuild/project"
+----
+
 == Resources
 
 * AWS Documentation https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-logs-loggroup.html[AWS::Logs::LogGroup]