Errors in Transition Radiation documentation

[nicowrobel]

The documentation of the CTR plugin contains multiple errors with many incorrectly named references to existing namespaces. A few examples:

• duplicate $g(\vec{p})$ - listing in variable list
• position attribute is called location in .param files section
• many more instances of incorrect naming from section Frequency Range onwards (linear_frequencies is actually called linearFrequencies in code etc.)