Add examples that use the 'site' dimension

[mauzey1]

Resolves #997

Adds Python, C, and Fortran examples that create datasets with 'site' as a dimension. Below is an excerpt from a file generated by one of the examples.

dimensions:
        time = UNLIMITED ; // (2 currently)
        site = 126 ;
        bnds = 2 ;
        vertices = 2 ;
variables:
        double time(time) ;
                time:bounds = "time_bnds" ;
                time:units = "days since 1979-01-01" ;
                time:calendar = "360_day" ;
                time:axis = "T" ;
                time:long_name = "Time Points" ;
                time:standard_name = "time" ;
        double time_bnds(time, bnds) ;
        int site(site) ;
                site:long_name = "site index" ;
        double latitude(site) ;
                latitude:standard_name = "latitude" ;
                latitude:long_name = "latitude" ;
                latitude:units = "degrees_north" ;
                latitude:missing_value = 1.e+20 ;
                latitude:_FillValue = 1.e+20 ;
                latitude:bounds = "vertices_latitude" ;
        double longitude(site) ;
                longitude:standard_name = "longitude" ;
                longitude:long_name = "longitude" ;
                longitude:units = "degrees_east" ;
                longitude:missing_value = 1.e+20 ;
                longitude:_FillValue = 1.e+20 ;
                longitude:bounds = "vertices_longitude" ;
        double vertices_latitude(site, vertices) ;
                vertices_latitude:units = "degrees_north" ;
                vertices_latitude:missing_value = 1.e+20 ;
                vertices_latitude:_FillValue = 1.e+20 ;
        double vertices_longitude(site, vertices) ;
                vertices_longitude:units = "degrees_east" ;
                vertices_longitude:missing_value = 1.e+20 ;
                vertices_longitude:_FillValue = 1.e+20 ;
        double height ;
                height:units = "m" ;
                height:axis = "Z" ;
                height:positive = "up" ;
                height:long_name = "height" ;
                height:standard_name = "height" ;
        float tas(time, site) ;
                tas:standard_name = "air_temperature" ;
                tas:long_name = "Near-Surface Air Temperature" ;
                tas:units = "K" ;
                tas:cell_methods = "area: point time: point" ;
                tas:history = "2026-09-11T22:53:16Z altered by CMOR: Treated scalar dimension: \'height\'." ;
                tas:coordinates = "height latitude longitude" ;
                tas:missing_value = 1.e+20f ;
                tas:_FillValue = 1.e+20f ;

[taylor13]

The output file produced by this example here looks perfect, and I didn't see any issues with the coding.