Added LogbookEntry model

[GrandMoff100]

Closes #64

[GrandMoff100]

MegaLinter status: ⚠️ WARNING

Descriptor	Linter	Files	Fixed	Errors	Elapsed time
⚠️ ACTION	actionlint	4		2	0.08s
✅ CREDENTIALS	secretlint	yes		no	0.92s
✅ CSS	stylelint	1	0	0	1.04s
✅ GIT	git_diff	yes		no	0.01s
✅ JSON	eslint-plugin-jsonc	2	0	0	0.89s
✅ JSON	jsonlint	2		0	0.53s
✅ JSON	prettier	2	0	0	1.07s
✅ JSON	v8r	2		0	1.78s
✅ MARKDOWN	markdownlint	6	0	0	0.35s
⚠️ MARKDOWN	markdown-link-check	6		1	1.86s
✅ MARKDOWN	markdown-table-formatter	6	0	0	0.26s
⚠️ SPELL	cspell	27		1	0.59s
✅ SPELL	misspell	27	0	0	0.06s
✅ YAML	prettier	7	0	0	1.29s
✅ YAML	v8r	7		0	5.89s
✅ YAML	yamllint	7		0	0.17s

See errors details in artifact MegaLinter reports on CI Job page