Add parameter units to documentation

[robotopia]

For the fitted parameters that are not dimensionless, add which units they are in to the documentation.

[harvey0908]

Hi Nick. I recently found an article with potential valuable pulsar data for our database. I've organized the data and need your help in verifying and incorporating it.The email has already been sent to you.

[robotopia]

@harvey0908 Perhaps your comment above should be in a separate issue?