Updated OAuth spelling and README file

[DevMahmoudMustafa]

قمI updated the spelling of the word OAuth because there was a difference in the word written in the config file and the entity file, and I updated the connection method from JWT to OAuth in the README file.

[dienht]

There is one error in line 59, Entry.php.

        if (strtolower(config('zoom.authentication_method')) === 'OAuth') {

It must change to:

        if (strtolower(config('zoom.authentication_method')) === 'oauth') {

Full method:

    public function newRequest()
    {
        if (strtolower(config('zoom.authentication_method')) === 'oauth') {
            return $this->oauthRequest();
        }

        throw new \ErrorException( "authentication_method " . config('zoom.authentication_method') . ' not found');
    }

I test, and it work. Thanks

[MAHMOUD202020]

Thank you, I will do that