Typo: ringer -> wringer

Fix pureLog in support.js to match the implemenation in the book

Added missing link to append

fix(ch05): hint change

- replace `flip` with `append`

Ch08: fix findParam to make usage of Maybe reasonable

Fix ch07

The expression is "through the wringer" - https://grammarist.com/usage/put-though-the-wringer-vs-put-through-the-ringer/

* reword discussion of how pure functions preserve referential transparency

* typo: bevhavior --> behavior

Traversable Maybe missing return in class method sequence

ch09: update markdown to reflect implementation

Fix Hindley-Milner Comment

ch05: replace join with intercalate

Update ch07.md

Ch09: fix example log function in section Mixing Metaphors

Improve formatting of nested chain calls in Chapter 09

The code just blow the example differs from the documented output see below.

// -- Impure calling code ----------------------------------------------

// run it by calling $value()!
findParam('searchTerm').$value();
// Just([['searchTerm', 'wafflehouse']])

Fix nodejs deprecation warnings

Related to #484