docs: add docs for RTD #1233

Job	Run time
Build	27s
Build	27s
Integration (1.7.*, 5.21/stable, lxd, 5.21, 2.9)	33m 33s
Integration (1.7.*, 5.21/stable, lxd, 5.21, 2.9)	33m 33s
Integration (1.7.*, 5.21/stable, lxd, 5.21, 3)	27m 45s
Integration (1.7.*, 5.21/stable, lxd, 5.21, 3)	27m 45s
Integration (1.7.*, 5.21/stable, microk8s, 1.28-strict, 3.1)	44m 57s
Integration (1.7.*, 5.21/stable, microk8s, 1.28-strict, 3.1)	44m 57s
Integration (1.7.*, 5.21/stable, microk8s, 1.28-strict, 3)	13m 11s
Integration (1.7.*, 5.21/stable, microk8s, 1.28-strict, 3)	13m 11s
Integration (1.8.*, 5.21/stable, lxd, 5.21, 2.9)	33m 3s
Integration (1.8.*, 5.21/stable, lxd, 5.21, 2.9)	33m 3s
Integration (1.8.*, 5.21/stable, lxd, 5.21, 3)	32m 33s
Integration (1.8.*, 5.21/stable, lxd, 5.21, 3)	32m 33s
Integration (1.8.*, 5.21/stable, microk8s, 1.28-strict, 3.1)	45m 12s
Integration (1.8.*, 5.21/stable, microk8s, 1.28-strict, 3.1)	45m 12s
Integration (1.8.*, 5.21/stable, microk8s, 1.28-strict, 3)	12m 55s
Integration (1.8.*, 5.21/stable, microk8s, 1.28-strict, 3)	12m 55s
Integration (1.9.*, 5.21/stable, lxd, 5.21, 2.9)	14m 4s
Integration (1.9.*, 5.21/stable, lxd, 5.21, 2.9)	14m 4s
Integration (1.9.*, 5.21/stable, lxd, 5.21, 3)	14m 25s
Integration (1.9.*, 5.21/stable, lxd, 5.21, 3)	39m 5s
Integration (1.9.*, 5.21/stable, microk8s, 1.28-strict, 3.1)	45m 11s
Integration (1.9.*, 5.21/stable, microk8s, 1.28-strict, 3.1)	45m 11s
Integration (1.9.*, 5.21/stable, microk8s, 1.28-strict, 3)	11m 55s
Integration (1.9.*, 5.21/stable, microk8s, 1.28-strict, 3)	11m 55s
	11h 23m 2s

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