xo-ratio: README elaboration

README.md

@@ -11,6 +11,9 @@ Relative to `std::ratio`:
 3. Provides concept support (with c++20)
 4. Requires modern (c++17) support to achieve this
 
+Relative to `boost::ratio`:
+1. Streamlined, assumes modern compiler support
+
 ## Getting Started
 
 ### install dependencies
@@ -18,11 +21,45 @@ Relative to `std::ratio`:
 - [github/Rconybea/xo-cmake](https://github.com/Rconybea/xo-cmake) cmake macros
 - [github/Rconybea/xo-flatstring](https://github.com/Rconybea/xo-flatstring) fixed-capacity strings
 
+### clone xo-ratio
+
+```
+$ cd ~/proj   # for example
+$ git clone https://github.com/Rconybea/xo-ratio
+```
+
 ### build + install
 ```
 $ cd xo-ratio
 $ PREFIX=/usr/local # for example
 $ BUILDDIR=.build   # for example
 $ make ${BUILDDIR}
-$ cmake -DCMAKE_PREFIX_PATH=${PREFIX} -B ${BUILDDIR}
+$ cmake --build .build
+$ cmake --install .build
+```
+
+### build with unit test coverage
+```
+$ cd xo-ratio
+$ mkdir .build-ccov
+$ cmake -DCMAKE_BUILD_TYPE=coverage -B .build-ccov
+$ cmake --build .build-ccov
+```
+
+run coverage-enabled unit tests
+```
+$ cmake --build .build-ccov -- test
+```
+
+generate html+text coverage report
+```
+$ cmake --build .build-ccov -- ccov
+```
+
+browse to `.build-ccov/ccov/html/index.html`
+
+### LSP support
+```
+$ cd xo-ratio
+$ ln -s .build/compile_commands.json
 ```