Add some more nice guides

Author: mkaput

website/pages/docs/guides/_meta.json

@@ -1,3 +1,6 @@
 {
-  "creating-a-new-package": ""
+  "creating-a-new-package": "",
+  "working-on-an-existing-package": "",
+  "dependencies": "",
+  "formatting": ""
 }

website/pages/docs/guides/dependencies.mdx

@@ -0,0 +1,81 @@
+import { Callout } from "nextra-theme-docs";
+
+# Managing dependencies
+
+Scarb manages dependencies by cloning packages from their Git repositories.
+To add a dependency, simply declare it in your `Scarb.toml`.
+
+<Callout type="info">
+  Using Git submodules as a foundation for package management is not an ideal
+  approach. Therefore, we plan to create a proper package registry in long term.
+</Callout>
+
+## Adding a dependency
+
+If your `Scarb.toml` doesn't already have a `[dependencies]{:toml}` section, add it, then list the package name and the URL to its Git repository.
+This example adds a dependency on the [`quaireaux`](https://github.com/keep-starknet-strange/quaireaux) package:
+
+```toml copy filename="Scarb.toml"
+[dependencies]
+quaireaux = { git = "https://github.com/keep-starknet-strange/quaireaux.git" }
+```
+
+In fact, it is always good to pin Git dependencies to concrete commits, otherwise Scarb would try to update this dependency each time it is executed.
+You can achieve this using one of the following extra fields that you can pass along `git{:toml}`: `branch{:toml}`, `tag{:toml}` and `rev{:toml}`.
+For example, in this guide we will pin to a concrete commit hash:
+
+```toml copy filename="Scarb.toml"
+[dependencies]
+quaireaux = { git = "https://github.com/keep-starknet-strange/quaireaux.git", rev = "041379c" }
+```
+
+<Callout type="info">
+  In the future this paragraph will be irrelevant, because Scarb will maintain a
+  lockfile. We track this feature in this issue:
+  [#126](https://github.com/software-mansion/scarb/issues/126).
+</Callout>
+
+Note, that if you want to add more dependencies, you do not have to add `[dependencies]{:toml}` for each package separately.
+
+Now, run `scarb build{:shell}`, and Scarb will fetch new dependencies and all of their dependencies.
+Then it will compile your package with all of these packages included:
+
+```shell copy
+scarb build
+```
+
+```text filename="Output"
+    Updating git repository https://github.com/keep-starknet-strange/quaireaux
+   Compiling hello_world v0.1.0 (/path/to/package/hello_world/Scarb.toml)
+    Finished release target(s) in 4 seconds
+```
+
+You can now use the `quaireaux` library in `lib.cairo`:
+
+```cairo copy filename="src/lib.cairo"
+use quaireaux::math::fibonacci;
+fn hello_world() -> felt {
+    fibonacci::fib(0, 1, 10)
+}
+```
+
+## Adding a dependency via `scarb add`
+
+If you prefer, you can also ask Scarb to edit `Scarb.toml` to add a dependency automagically for you.
+The `scarb add{:shell}` command accepts many parameters, matching all possibilities of expressing dependencies.
+It can also automatically keep the list sorted, if it already is.
+For example, the above example of dependency on `quaireaux`, can be also added like this:
+
+```shell copy
+scarb add quaireaux --git https://github.com/keep-starknet-strange/quaireaux.git --rev 041379c
+```
+
+## Removing a dependency
+
+To remove a dependency, simply remove related lines from your `Scarb.toml`.
+
+As a quick shortcut, the `scarb remove{:shell}` (also available in short `scarb rm{:shell}`) can clean the manifest automatically:
+
+```shell copy
+scarb rm quaireaux
+```

website/pages/docs/guides/formatting.mdx

@@ -0,0 +1,13 @@
+# Formatting
+
+Scarb comes with a built-in Cairo source code formatter:
+
+```shell copy
+scarb fmt
+```
+
+If you use continuous integration workflows in your project, you can also add a step to ensure the Cairo code is properly formatted:
+
+```shell copy
+scarb fmt --check
+```

website/pages/docs/guides/working-on-an-existing-package.mdx

@@ -0,0 +1,24 @@
+# Working on an Existing Scarb Package
+
+If you download an existing package that uses Scarb, it's really easy to get going.
+
+First, get the package from somewhere. For example, the [`quaireaux`](https://github.com/keep-starknet-strange/quaireaux) package is hosted on GitHub, and we 'll clone its repository using Git.
+
+```shell copy
+git clone https://github.com/keep-starknet-strange/quaireaux
+cd quaireaux
+cat Scarb.toml
+```
+
+Then to build it, use `scarb build{:shell}`:
+
+```shell copy
+scarb build
+```
+
+```text filename="Output"
+   Compiling quaireaux v0.1.0 (/path/to/package/quaireaux/Scarb.toml)
+    Finished release target(s) in 4 seconds
+```
+
+This will fetch all of the dependencies and then build them, along with the package.