added clangd config

compile_flags.txt

@@ -0,0 +1,22 @@
+-std=c99
+-Wno-unused-includes
+-Wall 
+-Wextra
+-Wduplicated-branches
+-Wduplicated-cond
+-Wformat=2
+-Wmissing-include-dirs
+-Wshadow
+-Werror=return-type
+-Werror=pointer-arith
+-Werror=init-self
+-Werror=incompatible-pointer-types
+-O0
+-g3
+-Isrc
+-Iinclude
+-Idependencies/BearSSL/inc
+-Idependencies/tlibc/include
+-Idependencies/tlibtoml/include
+-Idependencies/tsqlite/include
+-Idependencies/tim/include