feat: handle JAVA_OPTS #39

[CAMOBAP]

• Allow configuration of mn2pdf stack and heap space  #39
• PDF process: command-line change to mn2pdf stack and heap space metanorma-cli#326

[Intelligent2013]

@CAMOBAP I've tried to check how the JAVA_OPTS variable pass to the mn2pdf.

bundle exec metanorma -t iso -x pdf rice-en.final.adoc

The log ends with (PDF generated successfully):

...
Style: AnnexA-4-1:Preparation of test sample: subclause is only child
Style: (ID _0dccb2d5-c9ff-0779-c843-c5dfd40ef9c9): non-terms clauses cannot cross-reference terms clause (figureC-1)
Style: (ID _3d1d3043-177e-14c8-2c71-feb440fa631d): undated reference ISO 16634:-- should not contain specific elements

The previous version (main branch) outputs the mn2pdf command line:

Style: AnnexA-4-1:Preparation of test sample: subclause is only child
Style: (ID _0dccb2d5-c9ff-0779-c843-c5dfd40ef9c9): non-terms clauses cannot cross-reference terms clause (figureC-1)
Style: (ID _3d1d3043-177e-14c8-2c71-feb440fa631d): undated reference ISO 16634:-- should not contain specific elements
java -Xss10m -Xmx3g -Djava.awt.headless=true -Duser.home=C:/Users/IntlUser -jar C:/tools/ruby31/lib/ruby/gems/3.1.0/gems/mn2pdf-1.96/lib/../bin/mn2pdf.jar --xml-file "C:/Users/IntlUser/AppData/Local/Temp/rice-en.final20240806-20008-st3ac4.xml" --xsl-file "C:/tools/ruby31/lib/ruby/gems/3.1.0/bundler/gems/metanorma-iso-89aa394215f7/lib/isodoc/iso/iso.international-standard.xsl" --pdf-file "D:/Work/Metanorma/repositories/mn-samples-iso.copy14/sources/international-standard/rice-en.final.pdf" --syntax-highlight  --font-manifest "C:/Users/IntlUser/AppData/Local/Temp/fontist_locations20240806-20008-5597o2.yml"

Is there a way to return the mn2pdf output?
It's very convenient for debug purposes also.

[CAMOBAP]

@Intelligent2013 good catch, I will put it back

[Intelligent2013]

@CAMOBAP thank you!