Fix ADTxx descriptions

Created by: DanSGiesbrecht

As noted in #2264 (closed), Minicircuits RF tranformer descriptions did not match datasheet values.

Datasheet links:

• https://www.minicircuits.com/pdfs/ADT1-1WT-1+.pdf
• https://www.minicircuits.com/pdfs/ADT1.5-1+.pdf
• https://www.minicircuits.com/pdfs/ADT2-1T+.pdf
• https://www.minicircuits.com/pdfs/ADT2-1T-1P+.pdf
• https://www.minicircuits.com/pdfs/ADT3-1T+.pdf
• https://www.minicircuits.com/pdfs/ADT3-1T-75+.pdf
• https://www.minicircuits.com/pdfs/ADT4-1T+.pdf
• https://www.minicircuits.com/pdfs/ADT4-1WT+.pdf
• https://www.minicircuits.com/pdfs/ADT9-1T+.pdf
• https://www.minicircuits.com/pdfs/ADT16-1T+.pdf

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Checklist:

• Provide a URL to a datasheet for the symbol(s) you are contributing
• An example screenshot image is very helpful
• Ensure that the associated footprints match the official footprint library
  • A new fitting footprint must be submitted if the library does not yet contain one.
• If there are matching footprint PRs, provide link(s) as appropriate
• Check the output of the Travis automated check scripts - fix any errors as required
• Give a reason behind any intentional library convention rule violation.