Fix a typo and a grammar error (#5242)

Signed-off-by: Doğukan Teber <[email protected]>

Author: dogukanteber

docs/contributing/_index.md

@@ -15,7 +15,7 @@ You are welcome to create draft PRs at any stage of readiness - this
 can be helpful to ask for assistance or to develop an idea. But before
 a piece of work is finished it should:
 
-* Be organised into one or more commits, each of which has a commit message that describes all changes made in that commit ('why' more than 'what' - we can read the diffs to see the code that changed).
+* Be organized into one or more commits, each of which has a commit message that describes all changes made in that commit ('why' more than 'what' - we can read the diffs to see the code that changed).
 * Each commit should build towards the whole - don't leave in back-tracks and mistakes that you later corrected.
 * Have unit and/or [integration](./how-integration-tests-work.md) tests for new functionality or tests that would have caught the bug being fixed.
 * Include a CHANGELOG message if users of Cortex need to hear about what you did.
@@ -60,7 +60,7 @@ To run the integration tests suite please see "[How integration tests work](./ho
 
 ### Dependency management
 
-We uses [Go modules](https://golang.org/cmd/go/#hdr-Modules__module_versions__and_more) to manage dependencies on external packages.
+We use [Go modules](https://golang.org/cmd/go/#hdr-Modules__module_versions__and_more) to manage dependencies on external packages.
 This requires a working Go environment with version 1.11 or greater, git and [bzr](http://wiki.bazaar.canonical.com/Download) installed.
 
 To add or update a new dependency, use the `go get` command:

docs/contributing/how-to-update-the-build-image.md

@@ -10,7 +10,7 @@ The build image currently can only be updated by a Cortex maintainer. If you're
 1. Update `build-image/Dockerfile`
 1. Run `go env` and make sure `GOPROXY=https://proxy.golang.org,direct` (Go's default). Some environment may required `GOPROXY=direct`, and if you push a build image with this, build workflow on GitHub will take a lot longer to download modules.
 1. `docker login quay.io`. Note that pushing to `quay.io/cortexproject/build-image` repository can only be done by a maintainer.
-1. Build the and publish the image by using `make push-multiarch-build-image`. This will build and push multiplatform docker image (for linux/amd64 and linux/arm64).  Running this step successfully requires [Docker Buildx](https://docs.docker.com/buildx/working-with-buildx/), but does not require a specific platform.
+1. Build the and publish the image by using `make push-multiarch-build-image`. This will build and push multi-platform docker image (for linux/amd64 and linux/arm64).  Running this step successfully requires [Docker Buildx](https://docs.docker.com/buildx/working-with-buildx/), but does not require a specific platform.
 1. Replace the image tag in `.github/workflows/*` (_there may be multiple references_) and Makefile (variable `LATEST_BUILD_IMAGE_TAG`).
 1. If you are updating Go's runtime version be sure to change `actions/setup-go`'s `go-version` in ``.github/workflows/*`.
 1. Open a PR and make sure the CI with new build-image passes