Add Paddle backend support to poisson_1d_pideeponet and heat_sample (#…

…1828)

Backend paddle: DeepONetCartesianProd supports multi outputs (#1799)

Backend JAX: Transform bug fix (#1717)

Multi-dimentional output strategy for DeepONet in PyTorch (#1643)

Simplify dde.grad.hessian

Backend pytorch: Update the code to use GPU by default (#1530)

Add PI-DeepONet example for 1D Poisson equation (#1311)

Add diffusion reaction PI-DeepONet examples

Update research.rst (#1329)

Update docs about backend (#1287)