Fix curve closedness check in make_curve_mesh

See merge request inducer/meshmode!78

Boundary tag bit safer

See merge request inducer/meshmode!77

Fix some links and typos in the docs

See merge request inducer/meshmode!75

Add CI job to test examples on Github

Test examples during CI

See merge request inducer/meshmode!74

Add cartoon DG solver

See merge request inducer/meshmode!70

Fix some remaining issues with 1D meshes

See merge request !71

Remove extra vertex for closed 2D curves

See merge request !72

Before, the function was constructing a mesh that had
an extra vertex when the curve was closed. This was inconcistent
with the group's `vertex_indices`.