chore: further README tweaks

README.md

@@ -1,10 +1,10 @@
 <div align="center">
 
-<image src="fastlane/metadata/android/en-US/images/icon.png" height="100">
+<image src="fastlane/metadata/android/en-US/images/icon.png" style="border: .5px solid;" height="100">
 
 # Inflation Calculator
 
-![GitHub Workflow Status (with branch)](https://img.shields.io/github/actions/workflow/status/corenting/InflationCalculator/ci.yml?branch=master)
+[![GitHub Workflow Status (with branch)]](https://img.shields.io/github/actions/workflow/status/corenting/InflationCalculator/ci.yml?branch=master)
 [![GitHub release](https://img.shields.io/github/release/corenting/InflationCalculator.svg)](https://github.com/corenting/InflationCalculator/releases)
 [![GitHub license](https://img.shields.io/github/license/corenting/InflationCalculator.svg)](https://github.com/corenting/InflationCalculator/blob/master/LICENSE)
 
@@ -19,10 +19,10 @@ It supports the following countries:
 
 ## Data sources
 
-- USA: Bureau of Labor Statistics (Historical CPI-U), https://www.bls.gov/cpi/
-- UK: Office for National Statistics, https://www.ons.gov.uk/economy/inflationandpriceindices/timeseries/cdko/mm23
-- France: INSEE, https://www.insee.fr/fr/statistiques/serie/010605954
-- South Korea: Statistics Korea (Consumer Price Inflation Rate - 소비자물가상승률), https://www.index.go.kr/unity/potal/indicator/PotalIdxSearch.do?idxCd=4226&sttsCd=422601&clas_div=&idx_sys_cd=
+- USA: [Bureau of Labor Statistics (Historical CPI-U)](https://www.bls.gov/cpi/)
+- UK: [Office for National Statistics](https://www.ons.gov.uk/economy/inflationandpriceindices/timeseries/cdko/mm23)
+- France: [INSEE](https://www.insee.fr/fr/statistiques/serie/010605954)
+- South Korea: [Statistics Korea (Consumer Price Inflation Rate - 소비자물가상승률)](https://www.index.go.kr/unity/potal/indicator/PotalIdxSearch.do?idxCd=4226&sttsCd=422601&clas_div=&idx_sys_cd=)
 
 ## Screenshots