Added new docs section that warns against using dot notation for pipe…

[MehdiNV]

Description

Related to kedro-org/kedro-viz#1522

There is no warning given to users, in code or docs, from my understanding that advises them to avoid using . notation (which ordinarily indicates namespace pipeline). If . is used, it leads to disconnected and erratic behaving Kedro structures.

Development notes

• Added text in the md file, advising users to not add . when creating pipelines (and alternatively suggesting _)

QA notes

Documentation website should now have a new section at the bottom, warning users against creating pipelines w/ dot notation.

[stichbury]

Looks good to me but a few minor changes requested

[MehdiNV]

Looks good to me but a few minor changes requested

Good call! Have just committed new changes up

It's only the dot notation that breaks Kedro, other characters like ()!@£ etc should be completely fine. Is it better to be specific and say "Don't use dot notation" or keep it a bit expansive like it is now and say "Don't use improper characters like dot notation"?

[stichbury]

It's only the dot notation that breaks Kedro, other characters like ()!@£ etc should be completely fine. Is it better to be specific and say "Don't use dot notation" or keep it a bit expansive like it is now and say "Don't use improper characters like dot notation"?

I think if it's only the dot notation, then you should be specific about that, rather than restrict the reader (prevent them using other characters) unnecessarily.

[astrojuanlu]

Wondering if this could be made shorter and turned into a warning instead of a whole section of its own, something like

````warning
Kedro treats dots `.` in input and output names as namespace separators. If you do not want to use namespaces, avoid the use of dots in your input and output names, and use underscores `_` or other separators instead.

Example:

```python
pipeline([
  node(
    func=lambda x: x,
    inputs="input1kedro",
    outputs="outputs1.kedro",  # Will assume a namespace that doesn't exist!
  )
])
```
````

[stichbury]

I know where you're coming from as I thought the same initially. However, if you look in the context of the rest of that section, it fits quite well as an individual entry and if we modified this one to make it a warning, we should probably do the same with the others (and then it would look weird). So IMO it's OK as it is, in this case.

[astrojuanlu]

Maybe put it under a "Troubleshooting" section then?

[MehdiNV]

Maybe put it under a "Troubleshooting" section then?

@stichbury @astrojuanlu I'm personally fine w/ either, is there a preference? Docs is not my strong suit so not sure which way to personally lean myself

I assume with the Troubleshooting approach, we'd just create a new page named 'Troubleshooting' and move some of these texts there instead?

[stichbury]

I assume with the Troubleshooting approach, we'd just create a new page named 'Troubleshooting' and move some of these texts there instead?

Probably not, we don't need a page with a generic name because readers won't know what it contains. It's fine as it is -- I don't think we need to rename the section you've included it under. I'm happy with this now, so approving.