docs: improve How to use section in README.md (#780)

Author: tungbq

README.md

@@ -55,25 +55,25 @@ jobs:
           # working-directory: somedir
 
           # Optional: golangci-lint command line arguments.
-          # 
-          # Note: by default the `.golangci.yml` file should be at the root of the repository.
+          #
+          # Note: By default, the `.golangci.yml` file should be at the root of the repository.
           # The location of the configuration file can be changed by using `--config=`
           # args: --timeout=30m --config=/my/path/.golangci.yml --issues-exit-code=0 
 
           # Optional: show only new issues if it's a pull request. The default value is `false`.
           # only-new-issues: true
 
-          # Optional: if set to true then the all caching functionality will be complete disabled,
+          # Optional: if set to true, then all caching functionality will be completely disabled,
           #           takes precedence over all other caching options.
           # skip-cache: true
 
-          # Optional: if set to true then the action don't cache or restore ~/go/pkg.
+          # Optional: if set to true, then the action won't cache or restore ~/go/pkg.
           # skip-pkg-cache: true
 
-          # Optional: if set to true then the action don't cache or restore ~/.cache/go-build.
+          # Optional: if set to true, then the action won't cache or restore ~/.cache/go-build.
           # skip-build-cache: true
-          
-          # Optional:The mode to install golangci-lint. It can be 'binary' or 'goinstall'.
+
+          # Optional: The mode to install golangci-lint. It can be 'binary' or 'goinstall'.
           # install-mode: "goinstall"
 ```