Fails if a file at the path provided in config does not exist. No way to opt out of this

**Do you want to request a *feature* or report a *bug*?**
Request a feature

**What is the current behavior?**
I am currently running this tool within an nx mono repo. Nx has the ability to only build based on affected changes. That being said there may be valid cases where the paths supplied to the size tool in the package file do not exist. For example I am pointing the size tool at the the app file like so.

"size-limit": [
{
"limit": "3.2 s",
"path": [
"dist/app1/**/.*/**/_app-*.js"
]
},
{
"limit": "150 kB",
"path": [
"dist/app2/**/.*/**/_app-*.js"
]
}
]

As it stands if I have not changed my code I wont have a build output. This is not something easily known when running the size tool.

The issue is that size fails if the path provided does not exist. Would be great for this to be optional. Something like a flag I can provide to not fail `size-limit --ignoreIfFileMissing`