Use mermaid

design/src/docs/anatomy.md

@@ -257,7 +257,19 @@ pub struct AwsJson11;
 
 We can "upgrade" a model service to a HTTP service using `FromRequest` and `IntoResponse` described in the prior section:
 
-![Upgrade Data Flow Diagram](imgs/upgrade-dfd.png)
+```mermaid
+stateDiagram-v2
+ direction LR
+ HttpService: HTTP Service
+ [*] --> from_request: HTTP Request
+ state HttpService {
+ direction LR
+ ModelService: Model Service
+ from_request --> ModelService: Model Input
+ ModelService --> into_response: Model Output
+ }
+ into_response --> [*]: HTTP Response
+```
 
 This is formalized by the [`Upgrade<Protocol, Op, S>`](https://github.com/awslabs/smithy-rs/blob/4c5cbc39384f0d949d7693eb87b5853fe72629cd/rust-runtime/aws-smithy-http-server/src/operation/upgrade.rs#L76-L84) HTTP service. The `tower::Service` implementation is approximately:
 
@@ -292,7 +304,17 @@ There is an associated `Layer`, `UpgradeLayer<P, Op, B>` which constructs `Upgra
 
 The upgrade procedure is finalized by the application of the `Layer` `L`, referenced in `Operation<S, L>`. In this way the entire upgrade procedure takes an `Operation<S, L>` and returns a HTTP service.
 
-![Upgradable Diagram](imgs/upgradable.png)
+```mermaid
+stateDiagram-v2
+ direction LR
+ [*] --> S: HTTP Request
+ state L {
+ state Upgrade {
+ S
+ }
+ }
+ S --> [*]: HTTP Response
+```
 
 Note that the `S` and `L` are specified by logic written, in Rust, by the customer, whereas `Upgrade`/`UpgradeLayer` is specified entirely by Smithy model via the protocol, [HTTP bindings](https://awslabs.github.io/smithy/2.0/spec/http-bindings.html), etc.
 
@@ -412,7 +434,21 @@ where
 
 The `RouterService` is the final piece necessary to form a functioning composition - it is used to aggregate together the HTTP services, created via the upgrade procedure, into a single HTTP service which can be presented to the customer.
 
-![RouterService](imgs/router.png)
+```mermaid
+stateDiagram
+state in <<fork>>
+ direction LR
+ [*] --> in
+ state RouterService {
+ direction LR
+ in --> ServiceA
+ in --> ServiceB
+ in --> ServiceC
+ }
+ ServiceA --> [*]
+ ServiceB --> [*]
+ ServiceC --> [*]
+```
 
 ## Builders
 
@@ -671,7 +707,38 @@ The `Upgradable::upgrade` method on `Operation<S, L>`, previously presented in [
  }
 ```
 
-![Upgradable Diagram](imgs/upgradable-plugin.png)
+```mermaid
+stateDiagram-v2
+ direction TB
+ Op1: Operation#60;S1, L1#62;
+ state Op1 {
+ direction LR
+ [*] --> S1 : HTTP Request
+ S1 --> [*]: HTTP Response
+ state L1 {
+ Upgrade1 : Upgrade
+ state Upgrade1 {
+ S1
+ }
+ }
+
+ }
+
+ Op2: Operation#60;S2, L2#62;
+ state Op2 {
+ direction LR
+ [*] --> S2: HTTP Request
+ S2 --> [*]: HTTP Response
+ state L2 {
+ Upgrade2 : Upgrade
+ state Upgrade2 {
+ S2
+ }
+ }
+ }
+
+ Op1 --> Op2 : Plugin#colon;#colon;map
+```
 
 An example `Plugin` implementation can be found in [aws-smithy-http-server/examples/pokemon-service/src/plugin.rs](https://github.com/awslabs/smithy-rs/blob/main/rust-runtime/aws-smithy-http-server/examples/pokemon-service/src/plugin.rs).