Refactored device component docs

docs/models/dcim/rearport.md

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+# Rear Ports
+
+Like front ports, rear ports are pass-through ports which represent the end of a particular cable segment in a path. Each rear port is defined with a number of positions: rear ports with more than one position can be mapped to multiple front ports. This can be useful for modeling instances where multiple paths share a common cable (for example, six different fiber connections sharing a 12-strand MPO cable).
+
+Note that front and rear ports need not necessarily reside on the actual front or rear device face. This terminology is used primarily to distinguish between the two components in a pass-through port pairing.