Auto merge of #11469 - nilclass:patch-1, r=weihanglo

resolver.md: Fix naming in example

### What does this PR try to resolve?

It fixes what I believe to be a typo in the documentation.

### How should we test and review this PR?

Adding the example as it was to a `Cargo.toml` prints this warning:
```
warning: unused manifest key: dependency
```

With the corrected version it does not.

Author: bors

src/doc/src/reference/resolver.md

@@ -249,7 +249,7 @@ situations:
   not currently being built. For example:
 
   ```toml
-  [dependency.common]
+  [dependencies.common]
   version = "1.0"
   features = ["f1"]