Add cisco_xr_show_eigrp_neighbors.textfsm

[GutturalOnion]

Add a textFSM template for the Cisco IOS-XR command "show eigrp neighbors".

[mjbear]

Add a textFSM template for the Cisco IOS-XR command "show eigrp neighbors".

Hi @GutturalOnion!

There are a few things that need added to this PR before it's ready.

1. The index file needs updated so this template can be used (index order matters)
2. Test data needs to be added so CI tests can run against this template to validate it works now and in the future. There are helper scripts to help with generating the structured test data from the raw CLI output.

Here are some tips on the development environment

Thank you!

[mjbear]

@GutturalOnion
I hope you're doing well.
Please visit this PR on GitHub to review my guidance from a few weeks ago (Aug 28).

Please respond back with any questions.
Thank you!

[mjbear]

@GutturalOnion
Please review the August 28 requested changes.
If you have any questions, please respond back. We're here to assist.