Fix escaped backticks in README code blocks

The code blocks had backslash-escaped backticks which broke markdown preview.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

README.md

@@ -21,9 +21,9 @@ Built for JetStream from the ground up, not bolted on.
 
 ## Installation
 
-\`\`\`bash
+```bash
 go get git.flowmade.one/flowmade-one/aether
-\`\`\`
+```
 
 Requires Go 1.23 or later.
 
@@ -31,7 +31,7 @@ Requires Go 1.23 or later.
 
 Here is a minimal example showing event sourcing fundamentals: creating events, saving them to a store, and replaying to rebuild state.
 
-\`\`\`go
+```go
 package main
 
 import (
@@ -93,15 +93,15 @@ func main() {
 	fmt.Printf("  Total: $%.2f\n", state["total"])
 	fmt.Printf("  Tracking: %s\n", state["tracking"])
 }
-\`\`\`
+```
 
 Output:
-\`\`\`
+```
 Order state after replaying 2 events:
   Status: shipped
   Total: $99.99
   Tracking: FS123456
-\`\`\`
+```
 
 ## Key Concepts
 
@@ -117,7 +117,7 @@ Current state is always derived by replaying events. This gives you a complete a
 
 Each event for an actor must have a strictly increasing version number. This enables optimistic concurrency control:
 
-\`\`\`go
+```go
 currentVersion, _ := eventStore.GetLatestVersion(actorID)
 
 event := &aether.Event{
@@ -130,7 +130,7 @@ err := eventStore.SaveEvent(event)
 if errors.Is(err, aether.ErrVersionConflict) {
 	// Another writer saved first - reload and retry
 }
-\`\`\`
+```
 
 ## Documentation