Installation: needs overview of installation methods

### Describe the bug

https://docs.fluentd.org/installation

There are multiple installation methods.
However, there is no overview of it.
So, it is difficult to know which installation method to choose.

### Link to the problematic documentation

https://docs.fluentd.org/installation

### Expected explanation

Seems like a good idea to have the same overview as the next one.

https://www.fluentd.org/download

### Additional context

_No response_