Further tidy on Android instructions README.md (#7077)
* Further tidy on Android instructions README.md
Fixed some logic when following readme direction
* Clean up redundent information
A new user arriving will see simple directions on llama.cpp homepage
* corrected puncuation
Period after cmake, colon after termux
* re-word for clarity
method seems to be more correct, instead of alternative in this context
* Organized required packages per build type
building llama.cpp with NDK on a pc doesn't require installing clang, cmake, git, or wget in termux.
* README.md
corrected title
* fix trailing whitespace
