Remove `StorageVec` from missing features in the Sway Book
* [#428](https://github.com/FuelLabs/sway/issues/428): Arrays are currently immutable which means that changing elements of an array once initialized is not yet possible.
-* [#2035](https://github.com/FuelLabs/sway/issues/2035): Dynamic vectors _in storage_ have not yet been implemented. Only [vectors in memory](https://github.com/FuelLabs/sway/blob/master/sway-lib-std/src/vec.sw) are available at the moment.
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* [#1188](https://github.com/FuelLabs/sway/issues/1188): Mutable function arguments are not yet allowed except for `self`.
## General
