Renaming LoadNLogConfigFromSection to LoadConfigurationFromSection

[snakefoot]

Adjusted #412

Updated example:

                LogManager.Setup()
                    .SetupExtensions(s => s.AutoLoadAssemblies(false))
                    .LoadConfigurationFromSection(config);

Matches: NLog/NLog#3871 for NLog 4.7.1

Allow override of configSection to support "AzureFunctionsJobHost:NLog"

[codecov-io]

Codecov Report

Merging #418 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #418   +/-   ##
=======================================
  Coverage   82.29%   82.29%           
=======================================
  Files          14       14           
  Lines        1192     1192           
  Branches      195      195           
=======================================
  Hits          981      981           
  Misses        141      141           
  Partials       70       70           

Impacted Files	Coverage Δ
...xtensions.Logging/Config/SetupBuilderExtensions.cs	88.88% <ø> (ø)

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[304NotModified]

(note LoadNLogConfigFromSection was never released)