docs: add DNS rebinding protection guide #1214

Job	Run time
checks / readme-snippets	13s
checks / pre-commit	26s
checks / test (3.10, locked, windows-latest)	2m 15s
checks / test (3.11, lowest-direct, ubuntu-latest)	39s
checks / test (3.11, locked, ubuntu-latest)	47s
checks / test (3.12, lowest-direct, ubuntu-latest)	47s
checks / test (3.10, lowest-direct, ubuntu-latest)	43s
checks / test (3.11, locked, windows-latest)	2m 17s
checks / test (3.10, lowest-direct, windows-latest)	2m 40s
checks / test (3.10, locked, ubuntu-latest)	45s
checks / test (3.12, locked, windows-latest)	3m 17s
checks / test (3.11, lowest-direct, windows-latest)	2m 36s
checks / test (3.13, locked, ubuntu-latest)	43s
checks / test (3.13, locked, windows-latest)	2m 16s
checks / test (3.12, locked, ubuntu-latest)	51s
checks / test (3.14, lowest-direct, windows-latest)	2m 17s
checks / test (3.12, lowest-direct, windows-latest)	3m 24s
checks / test (3.14, lowest-direct, ubuntu-latest)	1m 12s
checks / test (3.13, lowest-direct, ubuntu-latest)	42s
checks / test (3.14, locked, ubuntu-latest)	2m 20s
checks / test (3.14, locked, windows-latest)	2m 58s
checks / test (3.13, lowest-direct, windows-latest)	2m 31s
all-green	5s
	36m 44s

Provide feedback