Migration Guides for MM and IPInfo

[Eddie51D]

Create pages to support customer migration from MM or IPInfo IPI properties to 51D equivalent properties.

This should be based on the publicly available property definitions.

[Eddie51D]

I've started a draft in a branch in documentation.

I wonder if as a future improvement we should move this to common-metadata. Add optional fields to the property structure for all competitor equivalent properties. The field would contain the name of the property from that competitor which aligns with the 51D property.

I'm not sure where the commentary would be recorded for reference in the website as I'm not 100% confident in allowed json structure.

e.g. for AccuracyRadiusMin.json
{
"Name": "AccuracyRadiusMin",
...
"MaxMind": ["accuracy_radius","Comment about this property"],
"IPinfo": "radius"
}

Or
e.g. for AccuracyRadiusMin.json
{
"Name": "AccuracyRadiusMin",
...
"MaxMind": "accuracy_radius",
"MaxMindComment": "Comment about this property migration",
"IPinfo": "radius"
}