Add priors documentation

docs/index.txt

@@ -11,6 +11,7 @@ Welcome to tupak's documentation!
    basics-of-parameter-estimation
    compact-binary-coalescence-parameter-estimation
    tupak-output
+   prior
    likelihood
    samplers
    writing-documentation

docs/likelihood.txt

+.. _likelihood:
+
 ==========
 Likelihood
 ==========
@@ -12,19 +14,12 @@ a `log_likelihood()` method.
 The default likelihood we use in the examples is `GravitationalWaveTransient`:
 
 .. autoclass:: tupak.likelihood.GravitationalWaveTransient
-    :members:
 
 We also provide a simpler likelihood
 
 .. autoclass:: tupak.likelihood.BasicGravitationalWaveTransient
-    :members:
 
 We provide an empty parent class which can be subclassed for alternative use
 cases
 
 .. autoclass:: tupak.likelihood.Likelihood
-    :members:
-
-
-
-

docs/samplers.txt

-==========
-Samplers
-==========
+.. run_sampler:
 
-Given a `likelihood` and `prior`, we can run parameter estimation using `run_sampler` 
+========
+Sampling
+========
+
+Given a :ref:`likelihood` and :ref:`priors`, we can run parameter estimation using the
+`run_sampler` function. This can be accessed via :code:`tupak.run_sampler` or
+:code:`tupak.sampler.run_sampler`. Here is the detailed API:
 
 .. autofunction:: tupak.sampler.run_sampler