update readme

[pawelru]

• remove r-universe from install instructions for simplicity
• remove link to the r-universe - this fixes url-checker

[github-actions]

Code Coverage Summary

Filename                  Stmts    Miss  Cover    Missing
----------------------  -------  ------  -------  -----------------------------------------------------------------------------------------------------
R/AddCardModule.R           146       2  98.63%   170, 207
R/ContentBlock.R             18       2  88.89%   57-63
R/DownloadModule.R          238      67  71.85%   98-104, 152, 183-188, 197-202, 205-210, 219-224, 227-232, 240-245, 248-253, 260-265, 268-273, 312-316
R/FileBlock.R                13       0  100.00%
R/LoadReporterModule.R      103      19  81.55%   100-105, 108-113, 119-124, 136
R/NewpageBlock.R              2       0  100.00%
R/PictureBlock.R             30       2  93.33%   20, 118
R/Previewer.R               372      95  74.46%   96-98, 101-102, 184-213, 217-219, 222, 289, 304, 306-309, 312, 315-323, 437-481
R/RcodeBlock.R               15       0  100.00%
R/Renderer.R                113      37  67.26%   97-112, 216, 224, 233, 235-256
R/ReportCard.R               84       3  96.43%   239, 244, 269
R/Reporter.R                107       6  94.39%   273-278
R/ResetModule.R              53       0  100.00%
R/SimpleReporter.R           32       0  100.00%
R/TableBlock.R                9       0  100.00%
R/TextBlock.R                13       0  100.00%
R/utils.R                   126      86  31.75%   7, 38-97, 99, 102-109, 137, 161-169, 206-215
R/yaml_utils.R               81       2  97.53%   78, 289
R/zzz.R                      14      10  28.57%   2-13, 19
TOTAL                      1569     331  78.90%

Diff against main

Filename      Stmts    Miss  Cover
----------  -------  ------  --------
TOTAL             0       0  +100.00%

Results for commit: 6a86f84

Minimum allowed coverage is 80%

♻️ This comment has been updated with latest results

[github-actions]

Unit Tests Summary

  1 files   18 suites   37s ⏱️
189 tests 189 ✅ 0 💤 0 ❌
329 runs  329 ✅ 0 💤 0 ❌

Results for commit 6a86f84.

♻️ This comment has been updated with latest results.