Fixed version metadata error (apache#7374)

### Motivation

```
Error: No 'original_id' field found in /pulsar/site2/website/versioned_docs/version-2.6.0/io-use.md. Perhaps you forgot to add it when importing prior versions of your docs?
    at forEach (/pulsar/site2/website/node_modules/docusaurus/lib/server/versionFallback.js:64:11)
    at Array.forEach (<anonymous>)
    at Object.<anonymous> (/pulsar/site2/website/node_modules/docusaurus/lib/server/versionFallback.js:52:7)
    at Module._compile (internal/modules/cjs/loader.js:778:30)
    at Module._compile (/pulsar/site2/website/node_modules/pirates/lib/index.js:99:24)
    at Module._extensions..js (internal/modules/cjs/loader.js:789:10)
    at Object.newLoader [as .js] (/pulsar/site2/website/node_modules/pirates/lib/index.js:104:7)
    at Module.load (internal/modules/cjs/loader.js:653:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:593:12)
    at Function.Module._load (internal/modules/cjs/loader.js:585:3)
error Command failed with exit code 1.
```

### Modifications

* Fixed io docs metadata error

site2/website/versioned_docs/version-2.6.0/io-use.md

@@ -1,4 +1,4 @@
---
+---
 id: version-2.6.0-io-use
 title: How to use Pulsar connectors
 sidebar_label: Use