-i and --input option with no source supplied crashes the tool

[SerpentBytes]

Environment Information

Operation System: macOS Monterey
Node version: v16.17.0

Bug Description

Running the tool with the -i or --input option with no source file or directory supplied crashes it.

Running with -i:

[Error: ENOENT: no such file or directory, scandir ''] {
  errno: -2,
  code: 'ENOENT',
  syscall: 'scandir',
  path: ''
}

Running with --input:

node:internal/fs/utils:347
    throw err;
    ^

Error: ENOENT: no such file or directory, open
    at Object.openSync (node:fs:594:3)
    at Object.readFileSync (node:fs:462:35)
    at getFileContent (/OSD600/repos/izyum-fork/bin/index.js:106:32)
    at proccessTextFile (/OSD600/repos/izyum-fork/bin/index.js:75:25)
    at proccessSingleFile (/OSD600/repos/izyum-fork/bin/index.js:85:5)
    at Object.<anonymous> (/OSD600/repos/izyum-fork/bin/index.js:120:9)
    at Module._compile (node:internal/modules/cjs/loader:1126:14)
    at Object.Module._extensions..js (node:internal/modules/cjs/loader:1180:10)
    at Module.load (node:internal/modules/cjs/loader:1004:32)
    at Function.Module._load (node:internal/modules/cjs/loader:839:12) {
  errno: -2,
  syscall: 'open',
  code: 'ENOENT'
}

[Myrfion]

Fix in #8