Extension:BypassSearch

The BypassSearch extension adds a user preference to go directly to creating a new page when the Go button is used and the target page doesn't exist.

When using the search box, the default behavior is to Go directly to an article if it exists, or if it doesn't, use the search engine to find the given term. This extension allows the user to specify (under the "Misc" tab of "my preferences") the he wants to go directly into creating a new page instead of activating the autosearch when the given article doesn't exist.

If, instead, you wish to force this behavior for everyone, you don't need to use this extension; rather, simply enable  globally.