update expired scrypt link

Add a link for reading the book or downloading it as pdf

Update 12.2.md

Update 05.6.md

fixed an IDE name in Chinese document

fix typo

the IDE should be `GoLand`

Fixing Else to else line-84

Update 08.1.md

Update 05.3.md

- 修改文字描述

小错误修改

minor adjustments to wording and formatting

fix a few typos in 12/2

Fixing some words

adding some russian

importing "strings" package

Strings package not imported but used line 361

Changed name Sam to Tom line 144

changed my Microsoft -> by Microsoft line 461

Spell change my -> by Microsoft

add `` on 'slice', line 322

changed 'Ferrramenta' to 'Ferramenta'

changed 'Extenção' to 'Extensão'

The same name repeated

Update 03.4.md

Typo and syntax fix