Summary:
Removed basic grammatical errors in two docs files: architecture.mdx and client-plugin-lifecycle.mdx
## Changelog
Update architecture.mdx and client-plugin-lifecycle.mdx docs
Pull Request resolved: https://github.com/facebook/flipper/pull/1459
Test Plan: There is only text change in documentation. The code is unchanged.
Reviewed By: cekkaewnumchai
Differential Revision: D23101962
Pulled By: passy
fbshipit-source-id: 24d9233d67a19745696b40ea6c2d3ac2d26231c3
eb09f7903b