chore: update illustrations for unleash anatomy (#7163)

Updating toggle to flag in unleash anatomy

website/docs/understanding-unleash/the-anatomy-of-unleash.mdx

@@ -142,7 +142,7 @@ Prior to 4.21, variants were independent of [environments](../reference/environm
 
 As of version 4.21, a feature can have different variants in different environments. For instance, a development environment might have no variants, while a production environment has 2 variants. Payloads, weightings and anything else can also differ between environments.
 
-<Figure img="/img/anatomy-of-unleash-variants-per-environment.png" caption="From Unleash 4.21 on, a feature flag can have different in each environment."/>
+<Figure img="/img/anatomy-of-unleash-variants-environment.png" caption="From Unleash 4.21 on, a feature flag can have different variants in each environment."/>
 
 
 ## Use case: changing website colors {#use-case}