Add coding exercises for Facebook interviews

Add attempts at solving coding problems to Briefcase.

scratch/facebook/onsite.txt

@@ -0,0 +1,22 @@
+** Behavior Interview **
+- Can I work in an unstructured environment?
+- Do I have a growth mindset?
+- How do I handle conflict?
+- Am I empathic?
+- Am I a self-starter?
+- What is my communication style?
+- Do I persevere?
+- <forgot to write this one down>
+
+** Design Interview **
+- requirement gathering, problem exploring
+- component analysis
+- quantitative analysis
+- trade-offs
+- bottlenecks, weaknesses
+- securing data (e.g. PII)
+
+Consider:
+- pagination
+- push/pull requests
+- API design