DOC: Fix additional join examples in "10 Minutes to pandas" #13029
- [x] closes #13029 

## [Current coverage](https://codecov.io/gh/pydata/pandas/pull/13171?src=pr) is **84.12%**

> Merging [#13171](https://codecov.io/gh/pydata/pandas/pull/13171?src=pr) into [master](https://codecov.io/gh/pydata/pandas/branch/master?src=pr) will not change coverage

``` diff
@@             master     #13171   diff @@
==========================================
  Files           138        138          
  Lines         50384      50384          
  Methods           0          0          
  Messages          0          0          
  Branches          0          0          
==========================================
  Hits          42382      42382          
  Misses         8002       8002          
  Partials          0          0          
```

> Powered by [Codecov](https://codecov.io?src=pr). Last updated by [82f54bd...633c7ff](https://codecov.io/gh/pydata/pandas/compare/82f54bd1dd53cb031e5d801405b34f062155d823...633c7ff3d1d15b5759db94bf97593583f9f2a300)
 thanks @Xndr7 
