feat: Support categories and keywords in forc manifest (#6974)

## Description

Related FuelLabs/forc.pub#30

## Checklist

- [ ] I have linked to any relevant issues.
- [ ] I have commented my code, particularly in hard-to-understand
areas.
- [ ] 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)
- [ ] I have added tests that prove my fix is effective or that my
feature works.
- [ ] I have added (or requested a maintainer to add) the necessary
`Breaking*` or `New Feature` labels where relevant.
- [ ] 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).
- [ ] I have requested a review from the relevant team or maintainers.

docs/book/src/forc/manifest_reference.md

@@ -12,6 +12,8 @@ The `Forc.toml` (the _manifest_ file) is a compulsory file for each package and
   * `homepage` — URL of the project homepage.
   * `repository` — URL of the project source repository.
   * `documentation` — URL of the project documentation.
+  * `categories` —  Categories of the project.
+  * `keywords` —  Keywords the project.
   * `entry` — The entry point for the compiler to start parsing from.
     * For the recommended way of selecting an entry point of large libraries please take a look at: [Libraries](./../sway-program-types/libraries.md)
   * `implicit-std` -  Controls whether provided `std` version (with the current `forc` version) will get added as a dependency _implicitly_. _Unless you know what you are doing, leave this as default._
@@ -39,6 +41,8 @@ An example `Forc.toml` is shown below. Under `[project]` the following fields ar
 * `homepage`
 * `repository`
 * `documentation`
+* `categories`
+* `keywords`
 
 Also for the following fields, a default value is provided so omitting them is allowed:
 
@@ -57,6 +61,8 @@ documentation = "https://example.com/"
 organization = "Fuel_Labs"
 license = "Apache-2.0"
 name = "wallet_contract"
+categories = ["example"]
+keywords = ["example"]
 
 [project.metadata]
 indexing = { namespace = "counter-contract", schema_path = "out/release/counter-contract-abi.json" }

forc-pkg/src/manifest/mod.rs

@@ -204,6 +204,8 @@ pub struct Project {
     pub homepage: Option<Url>,
     pub repository: Option<Url>,
     pub documentation: Option<Url>,
+    pub categories: Option<Vec<String>>,
+    pub keywords: Option<Vec<String>>,
     #[serde(default = "default_entry")]
     pub entry: String,
     pub implicit_std: Option<bool>,
@@ -1399,6 +1401,8 @@ mod tests {
             description: Some("test description".to_string()),
             homepage: None,
             documentation: None,
+            categories: None,
+            keywords: None,
             repository: None,
             organization: None,
             license: "Apache-2.0".to_string(),
@@ -1425,6 +1429,8 @@ mod tests {
             description: Some("test description".to_string()),
             homepage: Some(Url::parse("https://example.com").unwrap()),
             documentation: Some(Url::parse("https://docs.example.com").unwrap()),
+            categories: Some(vec!["test-category".to_string()]),
+            keywords: Some(vec!["test-keyword".to_string()]),
             repository: Some(Url::parse("https://example.com").unwrap()),
             organization: None,
             license: "Apache-2.0".to_string(),
@@ -1446,6 +1452,8 @@ mod tests {
         assert_eq!(project.repository, deserialized.repository);
         assert_eq!(project.metadata, deserialized.metadata);
         assert_eq!(project.metadata, None);
+        assert_eq!(project.categories, deserialized.categories);
+        assert_eq!(project.keywords, deserialized.keywords);
     }
 
     #[test]
@@ -1457,11 +1465,11 @@ mod tests {
             authors = ["Test Author"]
             description = "A test project"
             version = "1.0.0"
+            keywords = ["test", "project"]
+            categories = ["test"]
 
             [metadata]
             mykey = "https://example.com"
-            keywords = ["test", "project"]
-            categories = ["test"]
         "#;
 
         let project: Project = toml::from_str(toml_str).unwrap();
@@ -1474,10 +1482,6 @@ mod tests {
             table.get("mykey").unwrap().as_str().unwrap(),
             "https://example.com"
         );
-
-        let keywords = table.get("keywords").unwrap().as_array().unwrap();
-        assert_eq!(keywords[0].as_str().unwrap(), "test");
-        assert_eq!(keywords[1].as_str().unwrap(), "project");
     }
 
     #[test]