readme: fix a mistake
src: add instance method 'permutationQ()'
test: add instance method 'permutationQ()' testings
testing: remove the redundant testing
src: fix some mistakes and improve the readability
testing: fix some mistakes
readme: fix a mistake and add instance method 'permutationQ()'
src: improve the readability
src: add instance method 'matrixL()' for FullPivLU and CFullPivLU
test: add instance method 'matrixL()' testings
readme: add instance method 'matrixL()' api
src: add instance method 'matrixU()'
test: add instance method 'matrixU()' testings
readme: add instance method 'matrixU()' api
lint: add some files for linting pass
src: fix some mistake for instance method 'matrixL()'
test: update instance method 'matrixL()' testings
src: fix some mistakes and update api