feat(CMake): library only; update(README)

CMakeLists.txt

@@ -0,0 +1,29 @@
+cmake_minimum_required(VERSION 3.21)
+set(CMAKE_CXX_STANDARD 20)
+project(libbasen
+    VERSION 1.1.1
+    DESCRIPTION "c++20 encoding/decoding from arbitrary base"
+    LANGUAGES CXX
+)
+
+set(CXX_FLAGS "-Wall -Wextra -Werror -Wno-unused-result -O3")
+
+set(OBJS
+    base58
+    base64
+    baseN
+    hex
+    Exception
+    hash/sha256
+)
+set(SRCS)
+foreach(OBJ ${OBJS})
+    list(APPEND SRCS "src/${OBJ}.cpp")
+endforeach()
+
+add_library(basen ${SRCS})
+add_library(basen::basen ALIAS basen)
+target_include_directories(basen PUBLIC
+    $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
+    $<INSTALL_INTERFACE:include>
+)