Restructure pages docs

Closes #28688

See merge request !9527

#25437 Allow posting of just an emoji in comment; add /award slash command

Closes #25437

See merge request !9382

[ci skip]

Fix todos API endpoint application error

Closes #22951

See merge request !9351

Remove help from right dropdown

Closes #28837

See merge request !9594

But notice first.

See merge request !9364

[ci skip]

Grammar improvement in gitlab flow intro doc

Closes #28696

See merge request !9552

Fix concurrent access on builds/register

See merge request !9600

Don't declare constants in Struct

Closes #28808

See merge request !9582

Pagination only changes the page parameter.

Closes #28818

See merge request !9581

Show milestone ID in a consistent way

Closes #23602

See merge request !8820

Move all Pages related content to a single location

Closes #28819 and #28714

See merge request !9583

add /award slash command; Allow posting of just an emoji in comment

Fix Cycle Analytics -> Plan is loading forever

Closes #27622

See merge request !9577

Move `Group -> Members` to top-level, fix missing sub-nav for Subgroups

Closes #28678

See merge request !9589

Left align logo; increase max width of title

Closes #27934

See merge request !9588

Fix CI tables action buttons are hidden is smaller screens

Closes #28661

See merge request !9578

Document use of AirBnb js styleguide and eslint.

See merge request !9558

Fix 'New Tag' layout on Tags page

See merge request !9176

Signed-off-by: Rémy Coutable <remy@rymai.me>

API project create: Make name or path required

Closes #6073

See merge request !9416

Checks if key is present before accessing it

Fix broken test

Fix broken test

[ci skip]