Add the 'Algorithms' lesson to csintro (#425)

* Push the initial migration of the 'algorithms' lesson.

* Adjust lesson part names and link into main csintro page.

* Add 'Algoritms' lesson to SUMMARY

* Put standards page in there too.

docs/courses/csintro/algorithms.md

@@ -0,0 +1,22 @@
+# Algorithms
+
+This lesson introduces a conceptual framework for thinking of a computing device as something that uses code to process one or more inputs and send them to an output(s).
+
+## Lesson objectives
+Students will...
+
+* Understand the four components that make up a computer and their functions.
+* Understand that the micro:bit takes input, and after processing the input, produces output.
+* Learn the variety of different types of information the micro:bit takes in as input.
+* Apply this knowledge by creating a micro:bit program that takes input and produces an output.
+
+## Lesson plan
+
+1. [**Overview**: What is a computer and micro:bit hardware](/courses/csintro/algorithms/overview)
+2. [**Unplugged**: What's your function?](/courses/csintro/algorithms/unplugged)
+3. [**Activity**: Happy face, sad face](/courses/csintro/algorithms/activity)
+4. [**Project**: Fidget cube](/courses/csintro/algorithms/project)
+
+## Related standards
+
+[Targeted CSTA standards](/courses/csintro/algorithms/standards)