Documentation initial_condition/Uniform/values.

Documentation/ProjectFile/initial_condition/Uniform/c_Uniform.md

-\todo document
+A uniform initial condition is constant in time and space.

Documentation/ProjectFile/initial_condition/Uniform/t_value.md

-\todo document
+The given floating point value will be set as initial condition for the
+respective components on the entire domain.
+
+Same as values but for variables with one component only.  For multi component
+variables use the \ref ogs_file_param__initial_condition__Uniform__values
+"values tag".

Documentation/ProjectFile/initial_condition/Uniform/t_values.md

+A space separated list of floating point values, one for each component.
+The length of the list must match the number of the variable's components.
+
+The given floating point values will be set as initial condition for the
+respective components on the entire domain.
+
+For single component variables one can _optionally_ use the \ref
+ogs_file_param__initial_condition__Uniform__value "value tag".