adjust alt attributes for images

Author: fmalcher

blog/2018-02-rxjs-own-log-operator/README.md

@@ -189,7 +189,7 @@ export function log<T>(message?: string): OperatorFunction<T, T> {
 }
 ```
 
-![](observer-wrapper.png)
+![Illustration of the Observer Wrapper from the previous code snippet](observer-wrapper.png)
 
 
 If you take a look into the [RxJS source code](https://github.com/ReactiveX/rxjs/blob/cfbfaac36c847a1d09434a78ac1737c4a3149c5c/src/internal/operators/map.ts#L39-L46) you will see: that's exactly the approach they go for all the built-in operators.

blog/2018-04-swagger-codegen/README.md

@@ -56,7 +56,7 @@ In this article we will use the following API:
 
 Please feel free to explore it via [Swagger UI](https://api.angular.schule/swagger-ui/).
 
-[![Screenshot](swagger-ui.png)](https://api.angular.schule/swagger-ui/)
+[![Screenshot Swagger UI](swagger-ui.png)](https://api.angular.schule/swagger-ui/)
 
 Swagger codegen has a plenty of arguments to adjust.
 The minimal command line arguments are:

blog/2018-06-apollo-graphql-code-generator/README.md

@@ -27,8 +27,7 @@ Depending on the use-case, I favour a different approach to read and change in m
 
 ## Hello GraphQL
 
-<!--![Logo graphql](logo-graphql.svg?sanitize=true)-->
-<img src="https://angular-schule.github.io/website-articles/2018-06-apollo-graphql-code-generator/logo-graphql.svg?sanitize=true" width="75%">
+<img src="logo-graphql.svg" width="75%">
 
 One fundamental problem of a classical REST api is the amount of received data.
 Sometimes we fetch too much data, so there is data in the response we don't use.
@@ -156,8 +155,7 @@ You can learn more about the query language in [the official documentation](http
 
 ## Querying data with Apollo Angular
 
-<!--![Logo Apollo](logo-apollo.svg?sanitize=true)-->
-<img src="https://angular-schule.github.io/website-articles/2018-06-apollo-graphql-code-generator/logo-apollo.svg?sanitize=true" width="75%">
+<img src="logo-apollo.svg" width="75%">
 
 GraphQL has become very popular in recent times and there are a lot of implementations for various programming languages and frameworks.
 In the Angular world, the [Apollo](https://www.apollographql.com/) library is quite popular. 
@@ -286,8 +284,7 @@ Of course, other people have already done the hard work for us.
 
 ## Generating types with GraphQL code generator
 
-<!--![Logo GraphQL code generator](logo-graphql-code-generator.svg?sanitize=true)-->
-<img src="https://angular-schule.github.io/website-articles/2018-06-apollo-graphql-code-generator/logo-graphql-code-generator.svg?sanitize=true" width="50%">
+<img src="logo-graphql-code-generator.svg" width="50%">
 
 All information we need is already in the GraphQL schema.
 We are not going to use the [__Apollo__ GraphQL code generator](https://github.com/apollographql/apollo-codegen) here.

blog/2019-08-ng-deploy/README.md

@@ -181,7 +181,7 @@ ng run your-angular-project:deploy-firebase
 
 ## How to make your own deployment builder
 
-[![Teaser](ng-deploy-starter-project.jpg)](https://github.com/angular-schule/ngx-deploy-starter)
+[![](ng-deploy-starter-project.jpg)](https://github.com/angular-schule/ngx-deploy-starter)
 
 As a cloud platform provider (or as a fan of that service), you should consider to implement a dedicated deployment builder, too.
 The spectrum of possibilities is wide: Let's think about a deployment via FTP, to AWS, to Heroku, to Rackspace etc. – it's up to YOU to launch the next rocket! 🚀

blog/2021-12-rxjs-turn-signal/README.md

@@ -64,7 +64,7 @@ const stepTimeMs = 500;
 const rawSignal$ = timer(0, stepTimeMs).pipe(map(e => e % 2 === 0));
 ```
 
-![Marble Diagram](marble-map.svg)
+![Marble Diagram map](marble-map.svg)
 
 ## The trigger
 
@@ -128,7 +128,7 @@ press$.pipe(
 
 In the following marble diagram you can see that emissions from the source are being ignored as long as the signal is running.
 
-![Marble Diagram](marble-exhaustmap.svg)
+![Marble Diagram exhaustMap](marble-exhaustmap.svg)
 
 ## Displaying the signal
 
@@ -183,7 +183,7 @@ timer(0, 1000).pipe(
 ).subscribe(e => console.log(e));
 ```
 
-![Marble Diagram](marble-takeuntilsimple.svg)
+![Marble Diagram takeUntil](marble-takeuntilsimple.svg)
 
 Back to our turn signal, things become a little more challenging.
 The signalling period must be terminated when at least 3 cycles have passed *and* the trigger has been released.
@@ -246,7 +246,7 @@ press$.pipe(
 )
 ```
 
-![Marble Diagram](marble-takeuntil.svg)
+![Marble Diagram takeUntil with closingNotifier](marble-takeuntil.svg)
 
 ## Switching off the light
 
@@ -300,7 +300,7 @@ While a signal cycle is running, all other presses will be ignored.
 The signal ends after the trigger is released and at least 3 cycles have been finished.
 Regardless of how the interrupted signal ends, it will always switch off the light when it leaves the room.
 
-![Marble Diagram](marble-final.svg)
+![Marble Diagram with exhaustMap and the final result](marble-final.svg)
 
 Here is the full code: