Resolve "replace TABs with spaces in Manual.attributes"

See merge request OPAL/documentation/manual!88

Update Manual.attributes

See merge request OPAL/documentation/manual!87

Update Manual.attributes

See merge request OPAL/documentation/manual!86

Resolve "Fix links in gitlab environment"

Closes #25

See merge request OPAL/documentation/manual!85

All links to `gitlab.psi.ch` and `amas.web.psi.ch` are now defined as attributes in `Manual.attributes`. In a new branch, only this file must be changed to get the right links.

The header for rendering the chapters in `env-gitlab` is now defined in `env-gitlab.attributes`

Update Manual.macros

See merge request OPAL/documentation/manual!84

Update Manual.asciidoc

See merge request OPAL/documentation/manual!83

Update Manual.macros

See merge request OPAL/documentation/manual!82

Update Manual.asciidoc

See merge request OPAL/documentation/manual!81

Update Manual.macros

See merge request OPAL/documentation/manual!80

Update Manual.macros

See merge request OPAL/documentation/manual!79

Update Manual.asciidoc

See merge request OPAL/documentation/manual!78

Update Manual.asciidoc

See merge request OPAL/documentation/manual!77

Update Manual.asciidoc

See merge request OPAL/documentation/manual!76

Update Manual.asciidoc

See merge request OPAL/documentation/manual!75

Update Manual.asciidoc

See merge request OPAL/documentation/manual!74

Update Manual.macros

See merge request OPAL/documentation/manual!73

Update Manual.macros

See merge request OPAL/documentation/manual!72

Update Manual.asciidoc

See merge request OPAL/documentation/manual!71

Update Manual.asciidoc

See merge request OPAL/documentation/manual!70

Update Manual.asciidoc

See merge request OPAL/documentation/manual!69