Readme improvements

[guisua]

Just as a bit of feedback, maybe it would be nice to update the README to include the following:

• explain whether local IPs work for the OMBI_HOST -if not, make it clear that a public IP is needed
• clearly indicate whether http or https should/can/must be used
• in addition to the bot.env sample code, add a mocked but real bot.env sample
  • it wasn't immediately clear to me whether to use include <> or "" for the values

[guisua]

Maybe something like this?

|Parameter||Description|
|:--|:-:|:--|
|`OMBI_HOST`||Public IP address of your Ombi instance. Only `http://` is supported|
|`OMBI_KEY`||Go to your Ombi > Settings > Ombi (1st tab) > Api Key|
|`OMBI_BOT_TOKEN`||The BotFather gave you this token when creating your Telegram Bot|
|`OMBI_BOT_NAME`||The unique Telegram name you gave your bot when creating it using BotFather|
|`OMBI_USER_NAME`|OPTIONAL|Ombi admin username
|`BOT_ADMIN`|OPTIONAL|The admin's Telegram user id|
|`BOT_CHAT_ID`|OPTIONAL|The allowed Telegram chat's id|

At the end, your `bot.env` file should look something like this:

//```
OMBI_HOST=http://mydomain.com:12345
OMBI_KEY=abcdefghijklmnopqrstuvwxyz1234567890
OMBI_BOT_TOKEN=1234567890:abcdefghijklmnopqrstuvwxyz1234567890
OMBI_BOT_NAME=cool_bot_for_ombi
OMBI_USER_NAME=mike_sampleman
BOT_ADMIN=1234567890
BOT_CHAT_ID=1234567890
//```

[StackTraceYo]

sure - make a pull request