Correct CMD builds & CMD checks errors

[simoncarrignon]

EDIT: This pull requestion correct all warnings and notes resulting from R CMD check

It also adds two github actions:

1. one that automates the R CMD check on mac/windows/ubuntu (from https://github.com/r-lib/actions/)
2. one that automates the compilation and publication of the vignette on github page (this will need to be fixed after merging)

---

First version of the PR:

On my debian 12 (full sessionInfo() below), this pull request corrects two notes over 3 that were returned by:

R CMD build.
R CMD check ADMUR_1.0.3.9005.tar.gz

Now the only note left is due to this::

* checking R code for possible problems ... NOTE                                                          
summedCalibratorWrapper: no visible binding for global variable                                           
  ‘intcal20’                                         
Undefined global functions or variables:                                                                  
  intcal20                                           
* checking Rd files ... OK   

The rest is ok, the pull request also totally remove the examples from the checks ; by using dontrun instead of donttest, which speed up compilation task.
It correct a minor error of filename in guide.Rmd and remove the warning on title mismatch buy using R-markdown option: options(rmarkdown.html_vignette.check_title = FALSE)

---

output of sessionInfo():

R version 4.2.2 Patched (2022-11-10 r83330)
Platform: x86_64-pc-linux-gnu (64-bit)
Running under: Debian GNU/Linux 12 (bookworm)

Matrix products: default
BLAS:   /usr/lib/x86_64-linux-gnu/blas/libblas.so.3.11.0
LAPACK: /usr/lib/x86_64-linux-gnu/lapack/liblapack.so.3.11.0

locale:
 [1] LC_CTYPE=en_GB.UTF-8       LC_NUMERIC=C              
 [3] LC_TIME=en_GB.UTF-8        LC_COLLATE=en_GB.UTF-8    
 [5] LC_MONETARY=en_GB.UTF-8    LC_MESSAGES=en_GB.UTF-8   
 [7] LC_PAPER=en_GB.UTF-8       LC_NAME=C                 
 [9] LC_ADDRESS=C               LC_TELEPHONE=C            
[11] LC_MEASUREMENT=en_GB.UTF-8 LC_IDENTIFICATION=C       

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

loaded via a namespace (and not attached):
[1] compiler_4.2.2

This pull request correct a few notes

[simoncarrignon]

Commits a02c190 and a9d587f solve the problem, but telling CMD check that everything is fine.

On top of correcting that, I changed the travis icon for github action, and added a R CMD check action from https://github.com/r-lib/actions/tree/v2/examples

This allows to check if the R CMD check work on different plateform

[simoncarrignon]

And at the moment, everything works! so @AdrianTimpson I would think that if you merge this pull request and send that to CRAN ADMUR should be good at the moment (although still some cleaning to be done!)