Prepare for v0.22.0 release (#252)

## Type of change

<!--Delete points that do not apply-->

- Improvement (refactoring, restructuring repository, cleaning tech
debt, ...)

## Changes

The following changes have been made:

- Adds `Cargo.toml` for versioning 
- Updates instances that specify sway-libs version to `v0.22.0`
- Updates fuel-merkle to latest

## Notes

- Needed for v0.22.0 release

## Checklist

- [x] I have linked to any relevant issues.
- [x] I have commented my code, particularly in hard-to-understand
areas.
- [x] I have updated the documentation where relevant (API docs, the
reference, and the Sway book).
- [ ] If my change requires substantial documentation changes, I have
[requested support from the DevRel
team](https://github.com/FuelLabs/devrel-requests/issues/new/choose)
- [x] I have added tests that prove my fix is effective or that my
feature works.
- [x] I have added (or requested a maintainer to add) the necessary
`Breaking*` or `New Feature` labels where relevant.
- [x] I have done my best to ensure that my PR adheres to [the Fuel Labs
Code Review
Standards](https://github.com/FuelLabs/rfcs/blob/master/text/code-standards/external-contributors.md).
- [x] I have requested a review from the relevant team or maintainers.

Cargo.toml

@@ -0,0 +1,4 @@
+[package]
+name = "sway-libs"
+version = "0.22.0"
+edition = "2021"

README.md

@@ -69,7 +69,7 @@ For implementation details on the libraries please see the [Sway Libs Docs](http
 To import a library, the following dependency should be added to the project's `Forc.toml` file under `[dependencies]`.
 
 ```rust
-sway_libs = { git = "https://github.com/FuelLabs/sway-libs", tag = "v0.1.0" }
+sway_libs = { git = "https://github.com/FuelLabs/sway-libs", tag = "v0.22.0" }
 ```
 
 > **NOTE:** 

docs/book/src/getting_started/index.md

@@ -5,7 +5,7 @@
 To import any library, the following dependency should be added to the project's `Forc.toml` file under `[dependencies]`.
 
 ```sway
-sway_libs = { git = "https://github.com/FuelLabs/sway-libs", tag = "v0.1.0" }
+sway_libs = { git = "https://github.com/FuelLabs/sway-libs", tag = "v0.22.0" }
 ```
 
 For reference, here is a complete `Forc.toml` file:
@@ -18,7 +18,7 @@ license = "Apache-2.0"
 name = "MyProject"
 
 [dependencies]
-sway_libs = { git = "https://github.com/FuelLabs/sway-libs", tag = "v0.1.0" }
+sway_libs = { git = "https://github.com/FuelLabs/sway-libs", tag = "v0.22.0" }
 ```
 
 > **NOTE:** Be sure to set the tag to the latest release.

docs/book/src/merkle/index.md

@@ -68,7 +68,7 @@ To generate a Merkle Tree and corresponding proof for your Sway Smart Contract,
 The import the Fuel-Merkle crate, the following should be added to the project's `Cargo.toml` file under `[dependencies]`:
 
 ```sway
-fuel-merkle = { version = "0.33.0" }
+fuel-merkle = { version = "0.50.0" }
 ```
 
 > **NOTE** Make sure to use the latest version of the [fuel-merkle](https://crates.io/crates/fuel-merkle) crate.

examples/Cargo.toml

@@ -6,7 +6,7 @@ edition = "2021"
 license = "Apache-2.0"
 
 [dependencies]
-fuel-merkle = { version = "0.49.0" }
+fuel-merkle = { version = "0.50.0" }
 sha2 = { version = "0.10" }
 fuels = { version = "0.62.0", features = ["fuel-core-lib"] }
 tokio = { version = "1.12", features = ["rt", "macros"] }