Merge pull request #139 from wp-cli/regenerate-readme

Regenerate README file

Author: schlessera

README.md

@@ -130,7 +130,7 @@ There are no optionally available fields.
 Installs a WP-CLI package.
 
 ~~~
-wp package install <name|git|path|zip>
+wp package install <name|git|path|zip> [--insecure]
 ~~~
 
 Packages are required to be a valid Composer package, and can be
@@ -158,6 +158,9 @@ When installing a .zip file, WP-CLI extracts the package to
 		Names can optionally include a version constraint
 		(e.g. wp-cli/server-command:@stable).
 
+	[--insecure]
+		Retry downloads without certificate validation if TLS handshake fails. Note: This makes the request vulnerable to a MITM attack.
+
 **EXAMPLES**
 
     # Install a package hosted at a git URL.