Fix grammar and spelling mistakes in README

Signed-off-by: Mark Zhang <bf-109g2@hotmail.com>

README.md

@@ -7,7 +7,7 @@
 [![Go Report Card](https://goreportcard.com/badge/github.com/containerd/containerd)](https://goreportcard.com/report/github.com/containerd/containerd)
 [![CII Best Practices](https://bestpractices.coreinfrastructure.org/projects/1271/badge)](https://bestpractices.coreinfrastructure.org/projects/1271)
 
-containerd is an industry-standard container runtime with an emphasis on simplicity, robustness and portability. It is available as a daemon for Linux and Windows, which can manage the complete container lifecycle of its host system: image transfer and storage, container execution and supervision, low-level storage and network attachments, etc.
+containerd is an industry-standard container runtime with an emphasis on simplicity, robustness, and portability. It is available as a daemon for Linux and Windows, which can manage the complete container lifecycle of its host system: image transfer and storage, container execution and supervision, low-level storage and network attachments, etc.
 
 containerd is a member of CNCF with ['graduated'](https://landscape.cncf.io/?selected=containerd) status.
 
@@ -33,12 +33,12 @@ For containerd users already on v1.6.0-v1.6.3, there are known issues addressed
 We are a large inclusive OSS project that is welcoming help of any kind shape or form:
 * Documentation help is needed to make the product easier to consume and extend.
 * We need OSS community outreach/organizing help to get the word out; manage
-and create messaging and educational content; and to help with social media, community forums/groups, and google groups.
+and create messaging and educational content; and help with social media, community forums/groups, and google groups.
 * We are actively inviting new [security advisors](https://github.com/containerd/project/blob/main/GOVERNANCE.md#security-advisors) to join the team.
 * New sub-projects are being created, core and non-core that could use additional development help.
 * Each of the [containerd projects](https://github.com/containerd) has a list of issues currently being worked on or that need help resolving.
-  - If the issue has not already been assigned to someone, or has not made recent progress and you are interested, please inquire.
+  - If the issue has not already been assigned to someone or has not made recent progress and you are interested, please inquire.
-  - If you are interested in starting with a smaller / beginner level issue, look for issues with an `exp/beginner` tag, for example [containerd/containerd beginner issues.](https://github.com/containerd/containerd/issues?q=is%3Aissue+is%3Aopen+label%3Aexp%2Fbeginner)
+  - If you are interested in starting with a smaller/beginner-level issue, look for issues with an `exp/beginner` tag, for example [containerd/containerd beginner issues.](https://github.com/containerd/containerd/issues?q=is%3Aissue+is%3Aopen+label%3Aexp%2Fbeginner)
 
 ## Getting Started
 
@@ -115,7 +115,7 @@ func main() {
 
 ### Namespaces
 
-Namespaces allow multiple consumers to use the same containerd without conflicting with each other.  It has the benefit of sharing content but still having separation with containers and images.
+Namespaces allow multiple consumers to use the same containerd without conflicting with each other.  It has the benefit of sharing content while maintaining separation with containers and images.
 
 To set a namespace for requests to the API:
 
@@ -154,7 +154,7 @@ defer redis.Delete(context)
 
 ### OCI Runtime Specification
 
-containerd fully supports the OCI runtime specification for running containers.  We have built in functions to help you generate runtime specifications based on images as well as custom parameters.
+containerd fully supports the OCI runtime specification for running containers.  We have built-in functions to help you generate runtime specifications based on images as well as custom parameters.
 
 You can specify options when creating a container about how to modify the specification.
 
@@ -164,7 +164,7 @@ redis, err := client.NewContainer(context, "redis-master", containerd.WithNewSpe
 
 ### Root Filesystems
 
-containerd allows you to use overlay or snapshot filesystems with your containers.  It comes with built in support for overlayfs and btrfs.
+containerd allows you to use overlay or snapshot filesystems with your containers.  It comes with built-in support for overlayfs and btrfs.
 
 ```go
 // pull an image and unpack it into the configured snapshotter
@@ -317,14 +317,14 @@ A Kubernetes incubator project, [cri-tools](https://github.com/kubernetes-sigs/c
 
 ### Communication
 
-For async communication and long running discussions please use issues and pull requests on the github repo.
+For async communication and long-running discussions please use issues and pull requests on the GitHub repo.
 This will be the best place to discuss design and implementation.
 
 For sync communication catch us in the `#containerd` and `#containerd-dev` slack channels on Cloud Native Computing Foundation's (CNCF) slack - `cloud-native.slack.com`. Everyone is welcome to join and chat. [Get Invite to CNCF slack.](https://slack.cncf.io)
 
 ### Security audit
 
-A third party security audit was performed by Cure53 in 4Q2018; the [full report](docs/SECURITY_AUDIT.pdf) is available in our docs/ directory.
+A third-party security audit was performed by Cure53 in 4Q2018; the [full report](docs/SECURITY_AUDIT.pdf) is available in our docs/ directory.
 
 ### Reporting security issues
 
@@ -333,7 +333,7 @@ Please follow the instructions at [containerd/project](https://github.com/contai
 ## Licenses
 
 The containerd codebase is released under the [Apache 2.0 license](LICENSE).
-The README.md file, and files in the "docs" folder are licensed under the
+The README.md file and files in the "docs" folder are licensed under the
 Creative Commons Attribution 4.0 International License. You may obtain a
 copy of the license, titled CC-BY-4.0, at http://creativecommons.org/licenses/by/4.0/.