docs: replaced extends w/ implements keyword in classes

Author: dreamorosi

Diff for: docs/core/logger.md

@@ -151,7 +151,7 @@ Key | Example
 
     const logger = new Logger();
 
-    class Lambda extends LambdaInterface {
+    class Lambda implements LambdaInterface {
         // Decorate your handler class method
         @logger.injectLambdaContext()
         public async handler(_event: any, _context: any): Promise<void> {
@@ -589,7 +589,7 @@ For example, by setting the "sample rate" to `0.5`, roughly 50% of your lambda i
 
 ### Custom Log formatter (Bring Your Own Formatter)
 
-You can customize the structure (keys and values) of your log items by passing a custom log formatter, an object that extends the `LogFormatter` abstract class.
+You can customize the structure (keys and values) of your log items by passing a custom log formatter, an object that implements the `LogFormatter` abstract class.
 
 === "handler.ts"
 
@@ -631,7 +631,7 @@ This is how the `MyCompanyLogFormatter` (dummy name) would look like:
     // Replace this line with your own type
     type MyCompanyLog = LogAttributes;
 
-    class MyCompanyLogFormatter extends LogFormatter {
+    class MyCompanyLogFormatter implements LogFormatter {
 
         public formatAttributes(attributes: UnformattedAttributes): MyCompanyLog {
             return {

Diff for: docs/core/metrics.md

@@ -253,7 +253,7 @@ You can add default dimensions to your metrics by passing them as parameters in
     const metrics = new Metrics({ namespace: 'serverlessAirline', service: 'orders' });
     const DEFAULT_DIMENSIONS = { 'environment': 'prod', 'foo': 'bar' };
 
-    export class MyFunction extends LambdaInterface {
+    export class MyFunction implements LambdaInterface {
         // Decorate your handler class method
         @metrics.logMetrics({defaultDimensions: DEFAULT_DIMENSIONS})
         public handler(_event: any, _context: any): Promise<void> {
@@ -396,7 +396,7 @@ The `logMetrics` decorator of the metrics utility can be used when your Lambda h
 
     const metrics = new Metrics({ namespace: 'serverlessAirline', service: 'orders' });
 
-    export class MyFunction extends LambdaInterface {
+    export class MyFunction implements LambdaInterface {
 
         @metrics.logMetrics()
         public async handler(_event: any, _context: any): Promise<void> {
@@ -477,7 +477,7 @@ You can optionally capture cold start metrics with the `logMetrics` middleware o
 
     const metrics = new Metrics({namespace: 'serverlessAirline', service: 'orders' });
 
-    export class MyFunction extends LambdaInterface {
+    export class MyFunction implements LambdaInterface {
 
         @metrics.logMetrics({ captureColdStartMetric: true })
         public async handler(_event: any, _context: any): Promise<void> {
@@ -599,7 +599,7 @@ CloudWatch EMF uses the same dimensions across all your metrics. Use `singleMetr
 
     const metrics = new Metrics({ namespace: 'serverlessAirline', service: 'orders' });
 
-    class Lambda extends LambdaInterface {
+    class Lambda implements LambdaInterface {
 
         @metrics.logMetrics()
         public async handler(_event: any, _context: any): Promise<void> {

Diff for: docs/core/tracer.md

@@ -155,7 +155,7 @@ You can quickly start by importing the `Tracer` class, initialize it outside the
 
     const tracer = new Tracer({ serviceName: 'serverlessAirline' });
 
-    class Lambda extends LambdaInterface {
+    class Lambda implements LambdaInterface {
         // Decorate your handler class method
         @tracer.captureLambdaHandler()
         public async handler(_event: any, _context: any): Promise<void> {
@@ -262,7 +262,7 @@ You can trace other methods using the `captureMethod` decorator or manual instru
 
     const tracer = new Tracer({ serviceName: 'serverlessAirline' });
 
-    class Lambda extends LambdaInterface {
+    class Lambda implements LambdaInterface {
         // Decorate your class method
         @tracer.captureMethod()
         public getChargeId(): string {