demo: update math example from Mmark to Goldmark

exampleSite/content/post/writing-technical-content/index.md

@@ -55,16 +55,16 @@ $$\gamma_{n} = \frac{ \left | \left (\mathbf x_{n} - \mathbf x_{n-1} \right )^T
 
 Example **inline math** `$\nabla F(\mathbf{x}_{n})$` renders as $\nabla F(\mathbf{x}_{n})$.
 
-Example **multi-line math** using the `\\` math linebreak:
+Example **multi-line math** using the `\\\\` math linebreak:
 
 ```tex
-$$f(k;p_0^*) = \begin{cases} p_0^* & \text{if }k=1, \\
+$$f(k;p_0^*) = \begin{cases} p_0^* & \text{if }k=1, \\\\
 1-p_0^* & \text {if }k=0.\end{cases}$$
 ```
 
 renders as
 
-$$f(k;p_0^*) = \begin{cases} p_0^* & \text{if }k=1, \\
+$$f(k;p_0^*) = \begin{cases} p_0^* & \text{if }k=1, \\\\
 1-p_0^* & \text {if }k=0.\end{cases}$$
 
 ### Diagrams