feat: initial functionality (#8)

* chore: init rust library

* feat: build initial functionality of `FixedIndexVec`

* chore: setup github actions & dependabot

* chore: add clippy & fmt checks to workflow (#2)

* chore: add clippy & fmt checks to workflow

* chore: run ci on all pull requests, regardless of branch

* chore: remove unnecessary conditions from workflow triggers (#3)

* chore: remove unnecessary conditions from workflow triggers

* fix: rename `workflows` directory

* style: run `fmt` & `clippy`

* chore: run workflow for all PRs and core branch merges

* fix: correct workflow file syntax

* chore: rename primary workflow & add badge to readme (#4)

* feat: complete Rust API Checklist before publishing (#5)

* chore: create changelog

* chore: rename `enable-serde` feature to `serde`

* feat: add derives or implementations of common traits

* feat: add `From<HashMap` and `From<BTreeMap>` implementations

* feat: implement `Extend`

* test: validate Send and Sync implementations

* chore: remove redundant `Cargo.toml` metadata

* style: run clippy & fmt

* chore: add `release-plz` workflow (#6)