Entries with 📓 are my opinion.
📓 Replace passive voice with active voice. Most of the suggested edits employ active voice.
📓 There are many references to => but it is not called a 'hash rocket' until page 161--and then only once. Given that 'hash rocket' is a common term for this combination of symbols, the use of the name should be used much earlier and more frequently.
Functions mentioned outside of code blocks should be formatted function_name() (with empty parenthesis). Likewise, all variable names should be prefixed with $.
📓 The use of "will be discussed in full in Chapter X" is ... inaccurate. Remove "in full" or replace with "in detail."