[DOCS] Add attribute to escape minimal pt token link in Asciidoctor (#41613)

Author: jrodewig

docs/reference/analysis/tokenfilters/stemmer-tokenfilter.asciidoc

@@ -1,6 +1,12 @@
 [[analysis-stemmer-tokenfilter]]
 === Stemmer Token Filter
 
+// Adds attribute for the 'minimal_portuguese' stemmer values link.
+// This link contains ~, which is converted to subscript.
+// This attribute prevents that substitution.
+// See https://github.com/asciidoctor/asciidoctor/wiki/How-to-prevent-URLs-containing-formatting-characters-from-getting-mangled
+:min-pt-stemmer-values-url: http://www.inf.ufrgs.br/~buriol/papers/Orengo_CLEF07.pdf
+
 A filter that stems words (similar to `snowball`, but with more
 options). The `language`/`name` parameter controls the stemmer with the
 following available values:
@@ -47,7 +53,7 @@ http://dl.acm.org/citation.cfm?id=1141523&dl=ACM&coll=DL&CFID=179095584&CFTOKEN=
 http://www.illc.uva.nl/Publications/ResearchReports/MoL-2003-02.text.pdf[indonesian],
 http://www.ercim.eu/publication/ws-proceedings/CLEF2/savoy.pdf[light_italian],
 http://dl.acm.org/citation.cfm?id=1141523&dl=ACM&coll=DL&CFID=179095584&CFTOKEN=80067181[light_portuguese],
-http://www.inf.ufrgs.br/\~buriol/papers/Orengo_CLEF07.pdf[minimal_portuguese],
+{min-pt-stemmer-values-url}[minimal_portuguese],
 http://www.inf.ufrgs.br/\~viviane/rslp/index.htm[portuguese],
 http://doc.rero.ch/lm.php?url=1000%2C43%2C4%2C20091209094227-CA%2FDolamic_Ljiljana_-_Indexing_and_Searching_Strategies_for_the_Russian_20091209.pdf[light_russian],
 http://www.ercim.eu/publication/ws-proceedings/CLEF2/savoy.pdf[light_spanish],