Support non existent .htaccess files #11
Description
See #10 for some context. If there is no existing .htaccess file, then each run of gatsby build results in the redirects being added to the existing file. Ideally, the plugin should support appending to an existing .htaccess file in static/ as well as creating an empty file.
One approach could be to read the contents of static/.htaccess ourselves, and then append our redirects, and output this.
PRs welcome.