Replace github actions badge with one via shields.io for consistency

.github/workflows/build.yml

@@ -1,6 +1,5 @@
-# lower case name, because it's used as the label on badge on top of readme.
-# other badges also use lower case name, so this is for consistency
-name: linux
+# the name is used by the shields.io at top of readme
+name: build
 on:
   - push
   - pull_request

README.md

@@ -1,6 +1,6 @@
 # [![ZNC](https://wiki.znc.in/resources/assets/wiki.png)](https://znc.in) - An advanced IRC bouncer
 
-[![GitHub Actions Status](https://github.com/znc/znc/actions/workflows/build.yml/badge.svg)](https://github.com/znc/znc/actions/workflows/build.yml)
+[![GitHub Workflow Status](https://img.shields.io/github/workflow/status/znc/znc/build?label=linux)](https://github.com/znc/znc/actions/workflows/build.yml)
 [![Jenkins Build Status](https://img.shields.io/jenkins/s/https/jenkins.znc.in/job/znc/job/znc/job/master.svg?label=freebsd)](https://jenkins.znc.in/job/znc/job/znc/job/master/)
 [![AppVeyor Build status](https://img.shields.io/appveyor/ci/DarthGandalf/znc/master.svg?label=windows)](https://ci.appveyor.com/project/DarthGandalf/znc/branch/master)
 [![Bountysource](https://www.bountysource.com/badge/tracker?tracker_id=1759)](https://www.bountysource.com/trackers/1759-znc?utm_source=1759&utm_medium=shield&utm_campaign=TRACKER_BADGE)