chore: updates documentation examples

Updates documentation to improve code examples:

- Adds `fmt` import to Go example.
- Updates Python import path for `Nitric` resource.
- Corrects Python secret version printing example.

Author: davemooreuws

docs/index.mdx

@@ -61,6 +61,7 @@ Nitric.run()
 // !collapse(1:5) collapsed
 import (
   "context"
+  "fmt"
 
   "github.com/nitrictech/go-sdk/nitric"
   "github.com/nitrictech/go-sdk/nitric/apis"

docs/schedules.mdx

@@ -50,7 +50,7 @@ schedule('send-reminder').cron('0 22 * * 1-5', async (ctx) => {
 
 ```python !!
 from nitric.resources import schedule
-from nitric.resources import Nitric
+from nitric.application import Nitric
 
 # Run every 5 minutes
 processor = schedule("process-transactions")

docs/secrets.mdx

@@ -132,7 +132,7 @@ api_key = secret("api-key").allow("put")
 latest = await api_key.put("a new secret value")
 
 # We can get the version ID of our newly stored value
-latest.version
+print(latest.version)
 
 Nitric.run()
 ```