Document the Python Library #78

[IgorWilbert]

Registered the back-end functions used in PSlab from sciencelab.py. I think I got them all.

[CloudyPadmal]

Hello @IgorWilbert ! This is good work. There are few changes need to be done.

• The file name should be just README.md and it needs to be placed in the same folder as the sciencelab.py is
• We need to remove the private methods from this documentation (can be recognized from the two underscores at the beginning and at the end of the method name)
• No need to add def keywords. Only the method name and the parameters part is adequate
• Have the contend in the following format

<details>
<summary><code>Python method name with parameters</code></summary><br />

- Description of the method
- Parameters and the values they can take
  - One list item per each parameter
  - ...
- Return values and their meaning
</details>

[CloudyPadmal]

Duplicate #81