dev: add code coverage badge

.gitignore

@@ -1,2 +1,3 @@
 /target
 *.tar.gz
+cobertura.xml

Makefile

@@ -3,10 +3,15 @@ pre-commit:
 	cargo test -- --test-threads 1
 	cargo clippy -- -D clippy::all
 
+release:
+	cargo build --release
+
 # Sadly, this misses coverage for those integrations tests that use
 # assert_cmd, as it does not follow forks
 coverage:
 	cargo tarpaulin -- --test-threads 1
 
-release:
-	cargo build --release
+# TODO: add trigger for this target from within github actions
+codecov:
+	cargo tarpaulin --out Xml -- --test-threads 1
+	codecov-io

README.md

@@ -2,6 +2,7 @@
 Tool to draw low-resolution graphs in terminal.
 
 [![Rust](https://github.com/juan-leon/lowcharts/actions/workflows/test.yml/badge.svg)](https://github.com/juan-leon/lowcharts/actions/workflows/test.yml)
+[![codecov](https://codecov.io/gh/juan-leon/lowcharts/branch/main/graph/badge.svg?token=FNTO8M149T)](https://codecov.io/gh/juan-leon/lowcharts)
 [![dependency status](https://deps.rs/repo/github/juan-leon/lowcharts/status.svg)](https://deps.rs/repo/github/juan-leon/lowcharts)
 
 **lowcharts** is meant to be used in those scenarios where we have numerical