Readme update - making py executable

[StarT3]

I think it should be mentioned in Read me file.
Before trying to send anything with Zabbix, we should make zbxtg.py executable.
chmod +x zbxtg.py

[ableev]

It is already executable:

12:00:28 [reLosted] /tmp $ git clone https://github.com/ableev/Zabbix-in-Telegram.git
Cloning into 'Zabbix-in-Telegram'...
remote: Counting objects: 203, done.
remote: Total 203 (delta 0), reused 0 (delta 0), pack-reused 203
Receiving objects: 100% (203/203), 44.73 KiB | 0 bytes/s, done.
Resolving deltas: 100% (107/107), done.
Checking connectivity... done.
12:00:33 [reLosted] /tmp $ cd Zabbix-in-Telegram
12:00:36 [reLosted] /tmp/Zabbix-in-Telegram $ ls -la zbxtg.py
-rwxr-xr-x  1 lost  wheel  11591 Feb 10 12:00 zbxtg.py
12:00:39 [reLosted] /tmp/Zabbix-in-Telegram $

[StarT3]

Oh, i just copy-pasted .py contents to newly created files. And tested with "python zbxtg.py". It took me 30 minutes to understand why Zabbix could not send me anything while tests are going well.
Ok, if you think it should not be mentioned, let it be.