Readme

Audit and update README.md to reflect the current state of the library.

Step 1: Gather context

• Read src/Button2.h — extract every public method signature and constant
• Read the ## Unreleased and most recent versioned section of CHANGELOG.md
• Read README.md in full

Step 2: Identify gaps

Compare the public API in Button2.h against what README documents. Flag:

• Public methods present in the header but missing or outdated in README
• Methods in README that no longer exist in the header
• Default values or timing constants in README that differ from the header
• New features mentioned in CHANGELOG that have no README coverage

Do not flag internal helpers, private methods, or test infrastructure.

Step 3: Propose changes

List each gap with a one-line description of what needs to change. If $ARGUMENTS contains "audit", stop here and show the list without editing.

Step 4: Apply updates

For each gap, edit README.md in place:

• Match the existing style, formatting, and section structure exactly
• For new API entries, insert them in the same section and format as adjacent entries
• For removed entries, delete them cleanly without leaving stubs or comments
• Keep code examples consistent with the Arduino/ESP conventions in the file (no STL, no smart pointers)

Report what was changed when done.