Logging future warning

[tonykploomber]

closes #50

Changes:

• Add deprecation_warning func
• Add PR Template

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📚 Documentation preview 📚: https://ploomber-core--65.org.readthedocs.build/en/65/

[tonykploomber]

@edublancas
In the new change, I propose to make deprecation_warning accept the telemetry instance (optional)
Example, in the jupysql we can use:

from sql.telemetry import telemetry

deprecation_warning("you are using old feature", telemetry)

This is because we want to record the module (jupysql, ploomber...), which invokes the deprecation_warning.
Major benefit is we can see the different module

If we create the telemetry instance from ploomber-core and use it, we will hard to see which module invokes thedeprecation_warning, so I think take existing telemetry instance from modules is better idea

On posthug it will look like:

[neelasha23]

Do we need to add changelog entry? looks good besides this!

[edublancas]

please document this new approach here: https://ploomber-core.readthedocs.io/en/latest/deprecation.html

and add some context (the context is described in the original issue, which explains why we need this vs the existing deprecated module)