Embedded Falco version out of date

[richardmarshall]

It seems that the embedded version of Falco is currently at v1.0.0-rc2 which is a ways behind the current release of v1.4.0.

To make running the latest release (or a dev version built from source) of falco easier it would be nice if the extension could look in the PATH before falling back to the embedded version.

Additionally the repo listed for the falco-js package on npm (https://github.com/fastly/vscode-vcl) does not seem to exist or is private.

[sneakernuts]

@acme Any updates on this? Thanks!