Some Markdown Tips

Simply write sub topics here.

Did you know that you can write math equations here like this?

\[ \mu = \frac{1}{N} \sum_{i=0} x_i \]

The Master Method \[ \begin{align} \text{If } \quad T(n) & <= a T (\frac{n}{b}) + O(n^d) \\ \text{Then } \quad T(n) & = \begin{cases} O(n^d \log n) & \quad \text{if } a = b^d \text{ (Case 1)} \\ O(n^d) & \quad \text{if } a < b^d \text{ (Case 2)} \\ O(n^{\log_{b}{a} }) & \quad \text{if } a > b^d \text{ (Case 3)} \end{cases} \end{align} \]

Looks pretty awesome. More info see here

Add a table

|name   | length|
|----   |:-----:|
|oarfish| 10m?  |

Add a image

You can sort of use github issue page to store some pictures perhaps?

![image](https://user-images.githubusercontent.com/161689/111823245-02280e80-88e5-11eb-849d-b4d1e29c76ce.png)

Hidden session

And a hidden session like this to hide a graph:

<details>
<summary>Some hidden stuff here</summary>

![image](https://user-images.githubusercontent.com/161689/111823245-02280e80-88e5-11eb-849d-b4d1e29c76ce.png)

</details>

Some hidden code here

Embed an YouTube Video like this:

<iframe width="640" height="360" 
    src="https://www.youtube.com/embed/WbzNRTTrX0g?t=1557" 
    frameborder="0" allow="accelerometer; autoplay; clipboard-write;
    encrypted-media; gyroscope; picture-in-picture" allowfullscreen>
</iframe>

Mermaid graphs

See here and here.

```mermaid
graph TD
    A[Christmas] -->|Get money| B(Go shopping)
    B --> C{Let me think}
    C -->|One| D[Laptop]
    C -->|Two| E[iPhone]
    C -->|Three| F[fa:fa-car Car]
```

gives:

graph TD
    A[Christmas] -->|Get money| B(Go shopping)
    B --> C{Let me think}
    C -->|One| D[Laptop]
    C -->|Two| E[iPhone]
    C -->|Three| F[fa:fa-car Car]