docs(guides): spelling and grammar fixes (conventional-changelog#2521)

Author: scop

docs/guides-ci-setup.md

@@ -2,7 +2,7 @@
 
 Enforce commit conventions with confidence by linting on your CI servers with `commitlint`.
 
-This guide assumes you have a already configured `commitlint` for local usage.
+This guide assumes you have already configured `commitlint` for local usage.
 
 Follow the [Getting Started](./?id=getting-started) for basic installation and configuration instructions.
 

docs/guides-upgrade.md

@@ -90,7 +90,7 @@ module.exports = {
 }
 ```
 
-Refer to the [Rules Referece](reference-rules.md) for a list of all avaiable configuration options.
+Refer to the [Rules Reference](reference-rules.md) for a list of all available configuration options.
 
 There is also the [#commitlint](https://node-tooling.slack.com/messages/C7M8XJ4RL/) channel on the DevTools Slack workspace. Join us there and we'll do our best to help you with your migration.
 
@@ -165,7 +165,7 @@ echo 'module.exports = {extends: ["@commitlint/config-conventional"]};';
 
 ### Breaking changes
 
-#### Output on succesful commit will be ommited
+#### Output on successful commit will be omitted
 
 - You can use the `--verbose` flag to get positive output