enotes menu should not search directories

Created by: dtu-compute

Right now the website will add all pdf's in e.g /vol/website-enotes/02323/ to the enote menu even if they are in a sub directory.

02323 would like to be able to have sub directories in /vol/website-enotes/02323/ with pdf's (and aux files) that the website doesn't know about. They will use this to generate solutions and such together with the book in sharelatex. They then link to these in emails.

The menu should also ignore files that doesn't match *.pdf. Right now e.g. aux and txt files show up in the menu.

# tree /vol/website-enotes/02323/
/vol/website-enotes/02323/
├── chapter1-DataVisualization.pdf
├── chapter2-ProbabilitySimulation.pdf
├── chapter3-StatisticsNormalAssumption.pdf
├── chapter4-SimulationBasedStatistics.pdf
├── chapter5-SimpleLinearRegression.pdf
├── chapter6-MultipleLinearRegression.pdf
├── chapter7-ProportionsFrequencyTables.pdf
├── chapter8-StatisticsMultigroupANOVA.pdf
├── chapterA-formulas.pdf
└── files
    ├── book-IntroStatistics.aux
    ├── solutions-chapter1.pdf
    ├── solutions-chapter2.pdf
    ├── solutions-chapter3.pdf
    ├── solutions-chapter4.pdf
    ├── solutions-chapter5.pdf
    ├── solutions-chapter6.pdf
    ├── solutions-chapter7.pdf
    └── solutions-chapter8.pdf