MAJOR: Project rename and preparation for v1.0.0

I hope I haven't missed any for the renames!

lua/outline/ui.lua

@@ -0,0 +1,51 @@
+local M = {}
+
+M.hovered_hl_ns = vim.api.nvim_create_namespace 'hovered_item'
+
+function M.clear_hover_highlight(bufnr)
+  vim.api.nvim_buf_clear_namespace(bufnr, M.hovered_hl_ns, 0, -1)
+end
+
+function M.add_hover_highlight(bufnr, line, col_start)
+  vim.api.nvim_buf_add_highlight(
+    bufnr,
+    M.hovered_hl_ns,
+    'OutlineCurrent',
+    line,
+    col_start,
+    -1
+  )
+end
+
+function M.setup_highlights()
+  -- Setup the OutlineCurrent highlight group if it hasn't been done already by
+  -- a theme or manually set
+  if vim.fn.hlexists 'OutlineCurrent' == 0 then
+    local cline_hl = vim.api.nvim_get_hl_by_name('CursorLine', true)
+    local string_hl = vim.api.nvim_get_hl_by_name('String', true)
+
+    vim.api.nvim_set_hl(
+      0,
+      'OutlineCurrent',
+      { bg = cline_hl.background, fg = string_hl.foreground }
+    )
+  end
+
+  -- Some colorschemes do some funky things with the comment highlight, most
+  -- notably making them italic, which messes up the outline connector. Fix
+  -- this by copying the foreground color from the comment hl into a new
+  -- highlight.
+  local comment_fg_gui = vim.fn.synIDattr(
+    vim.fn.synIDtrans(vim.fn.hlID 'Comment'),
+    'fg',
+    'gui'
+  )
+
+  if vim.fn.hlexists 'OutlineConnector' == 0 then
+    vim.cmd(
+      string.format('hi OutlineConnector guifg=%s', comment_fg_gui)
+    )
+  end
+end
+
+return M