Remove redundant CI tests (appveyor, circleci) and rely only on github actions matrix windows/macos/ubuntu (#538)

* Update README.md
* Delete appveyor.yml
* Delete .circleci/config.yml

.circleci/config.yml

@@ -1,22 +0,0 @@
-version: 2.1
-executors: #(1)
-  exectr:
-      docker:
-      - image: cimg/base:edge-20.04
-    #docker:
-    #  - image: dockerben/cpptemplate:latest
-    # example, maybe setup my own image later
-    # https://thoughts-on-coding.com/2020/04/20/a-cpp-github-template-repository-utilizing-circleci-cmake-docker-and-doxygen/
-    # should look into Windows, Ubuntu, OSX executions in parallell with CircleCI ref https://circleci.com/docs/2.0/parallelism-faster-jobs/
-jobs:
-  build:
-    executor: exectr #(1)
-    steps:
-      - checkout 
-      - run: 
-          name: build_and_run
-          command: |
-            ./scripts/buildAndRunTests.sh
-      
-      
-      

README.md

@@ -108,14 +108,8 @@ You can find it here: https://kjellkod.wordpress.com/2015/06/30/the-worlds-faste
 
 
 ## <a name="continuous_integration">Continuous Integration</a>
-The g3log repository is evaluating both github actions and CircleCI for executing test coverage, installation and document generation. For windows the repo is still relying on appveyor.  In case you want to look into change any of these setups the following files are the ones of interest. 
-```
-1. appveyor --> g3log/appveyor.yml
-2. circleCI --> g3log/.circleci/config.yml
-3. github actions --> g3log/.github/workflows/*.yml
-
-
-```
+The g3log repository is evaluating github actions for executing test coverage, installation and document generation. In case you want to look into change any of these setups the following files are the ones of interest. 
+See `Actions` for matrix (ubuntu, macos, windows) testing as well as other actions for doc publishing. 
 
 
 ## <a name="feedback">Feedback</a>

appveyor.yml

@@ -1,37 +0,0 @@
-environment:
-  P: "c:/projects/libs"
-
-# Operating system (build VM template)
-os: Visual Studio 2022
-
-# scripts that are called at very beginning, before repo cloning
-#init:
-
-
-# clone directory
-clone_folder: c:\projects\g3log
-
-platform: x64
-configuration: Release
-
-install:
-  # by default, all script lines are interpreted as batch
-
-# scripts to run before build
-before_build:
-  - cd c:\projects\g3log\
-  - mkdir build
-  - cd build
-
-build_script:
-  - cmake  -G "Visual Studio 17" -A x64 -DADD_G3LOG_UNIT_TEST=ON -DWINDOWS_FUNCSIG=ON -DUSE_DYNAMIC_LOGGING_LEVELS=ON -DCHANGE_G3LOG_DEBUG_TO_DBUG=ON -DCMAKE_INSTALL_PREFIX=c:\g3log ..
-  - cmake --build . --config Release --target install
-
-# scripts to run after build
-after_build:
-  - cmd /c Release\g3log-FATAL-contract.exe || exit /B 0
-  - tree /A /F c:\g3log
-  - cpack -G "NSIS;ZIP"
-  - cpack -C Release
-  - ctest -C Release --verbose
-