`beckn:availabilityWindow` should be `beckn:availabilityWindows`

[dubeyAyush]

https://github.com/Beckn-One/DEG/blob/405fd47f7f209f84f94169e58a3cc8832ee0431a/docs/implementation-guides/v2/EV_Charging_V0.8-draft.md?plain=1#L3706

As beckn:availabilityWindow is an array please rename it to beckn:availabilityWindows

[anandp504]

@dubeyAyush It is not a good practice to have the fields signify whether they are plural or singular. The type array in the field definition will indicate whether multiple values are allowed.

[ravi-prakash-v]

This is a non-issue. Moving it to discussions.