Fixes for checks, improved implementation for ranger random survival forest

[krzyzinskim]

PR aimed at preparing a new version for CRAN release.

Changes:

• automated website building added for workflows
• updated website in /docs (to be deleted after successful automatic website generation on a separate branch)
• changes to DESCRIPTION -- updated list of authors
• fixes in examples and tests
• improved implementation for ranger random survival forest -- added support for cumulative hazard function predictions, speeding up implementation

[codecov-commenter]

Codecov Report

Merging #29 (f14a490) into master (8ee465f) will increase coverage by 1.61%.
Report is 7 commits behind head on master.
The diff coverage is 92.85%.

❗ Current head f14a490 differs from pull request most recent head b31ce32. Consider uploading reports for the commit b31ce32 to get more accurate results

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@@            Coverage Diff             @@
##           master      #29      +/-   ##
==========================================
+ Coverage   68.13%   69.74%   +1.61%     
==========================================
  Files          18       19       +1     
  Lines         819      876      +57     
==========================================
+ Hits          558      611      +53     
- Misses        261      265       +4     

Files	Coverage Δ
R/treeshap.R	83.33% <ø> (ø)
R/unify_catboost.R	89.33% <100.00%> (ø)
R/unify_gbm.R	97.29% <100.00%> (ø)
R/unify_lightgbm.R	94.00% <ø> (ø)
R/unify_ranger.R	96.77% <100.00%> (+0.34%)	⬆️
R/unify_randomForest.R	94.11% <0.00%> (ø)
R/unify_ranger_surv.R	92.59% <92.59%> (ø)

[mikolajsp]

Looks good