Add nord theme

See merge request !125

Signed-off-by: Andre Simon <[email protected]>

Recognise GNUmakefile as a makefile

See merge request !124

https://www.gnu.org/software/make/manual/html_node/Makefile-Names.html

GitLab CI: Add EditorConfig Validation

See merge request !123

Amend indentation in `plugins/outhtml_ansi_esc.lua` to pass EClint
validation tests.

Extend `.gitlab-ci.yml` to validate commits agains EditorConfig settings
via EClint, using the `./validate.sh` script.

Hugo Lang v1.1.0

See merge request !122

Update the Hugo syntax:

* Many bug fixes and improvements.
* New Kwd ID 2 group (IDs 2-3 shifted to 4-5).
* Added missing keywords and removed library tokens with assistance of
  Hugo creator Kent Tessman (@tessman).

EditorConfig

See merge request !121

Enforce consistent code styles for all batch scripts:

* Indent: 2 spaces.
* Trim trailing whitespace.
* Insert final new line.
* UTF-8 encoding.

Manually fix all scripts that didn't pass EClint validation.

Add `.bash` and `.fish` extensions (used in `extras/sh-completions/`)
to `.editorconfig` and `.gitattributes`, with same settings as `.sh`.

Enforce consistent code styles for all make-related files:

* Indent: tabs.
* Trim trailing whitespace.
* Insert final new line.
* UTF-8 encoding.

Bulk-fix all files that didn't pass EClint validation.

Enforce consistent code styles for all Lua files (.lua, .lang, .theme):

* Indent: 2 spaces.
* Trim trailing whitespace.
* Insert final new line.
* UTF-8 encoding.

Manually fix all scripts that didn't pass EClint validation (256 files).

Set executable permission on some `*.sh` scripts in the project.