Content and list view enhancement in cppguide.html

Fixes #806

Changes

Scope in programming refers to the visibility and accessibility of variables, functions, and other identifiers within a program. It plays a crucial role in preventing naming conflicts by limiting the visibility of identifiers to specific regions of code, such as within a function, block, or namespace.
Global scope refers to identifiers accessible throughout the entire program, while local scope refers to identifiers accessible only within a specific block or function. Nested scopes occur when one scope is contained within another, allowing identifiers declared in an outer scope to be accessed by inner scopes, but not vice versa.
Understanding scoping rules is essential for writing maintainable and error-free code, as it helps prevent unintended side effects and promotes modular design.

google / styleguide