v5.15.0

NeuralPDE v5.15.0

Diff since v5.14.0

Merged pull requests:

• build: bump mtk to v9 (#828) (@sathvikbhagavan)
• ci: add Downgrade CI (#831) (@sathvikbhagavan)
• docs: fix rendering (#832) (@sathvikbhagavan)
• refactor: correctly lower quadrature training strategy in NNODE (#836) (@sathvikbhagavan)
• feat: allow complex for NNODE (#839) (@sathvikbhagavan)

Closed issues:

• Allow batching with QuadratureStrategy in NNODE (#555)