fix(new-ds): fix broken link to template pugs

[gcruchon]

Related issue

Description of the issue

Can't build the news design system due to broken references to pug templates.

[09:01:00] Plumber found unhandled error:
 Error in plugin "gulp-pug"
Message:
    /Users/a188dt/dev/react-toolkit/storybook/design-system/src/components/demo/demo.pug:5
    3|     -const classDisplayComponent = `${setClass('demo__display', modifier, true)}`
    4|     -const tmplPath = absTmpl !== '' ? absTmpl : tmpl!== '' ? `./src/pages${activePath}/templates/${tmpl}.pug` : ''
  > 5|     -const htmlCode = tmplPath !== '' ? pugg.compileFile(tmplPath, { pretty: true }) : 'No HTML'
    6|     -const sassCode = sassPath !== '' ? fs.readFileSync(`node_modules/@axa-fr/${sassPath}`, 'utf8') : 'No style'
    7|     block
    8|     article(class=classComponent)

ENOENT: no such file or directory, open 'src/pages/style/icons/templates/arrowthin-left.pug'
    at ./src/pages/atoms/button/templates/button-icon.pug line 3
Details:
    errno: -2
    syscall: open
    code: ENOENT
    path: /Users/a188dt/dev/react-toolkit/storybook/design-system/src/components/demo/demo.pug

Person(s) for reviewing proposed changes

@samuel-gomez

[samuel-gomez-axa]

thank you @gcruchon