Some DataTable doc updates, rename Coord -> Coordinate and extract to module

docs/roadmap.md

@@ -6,7 +6,7 @@ hide:
 
 # Roadmap
 
-We ([textualize.io](https://www.textualize.io/)) are actively building and maintaining Textual. 
+We ([textualize.io](https://www.textualize.io/)) are actively building and maintaining Textual.
 
 We have many new features in the pipeline. This page will keep track of that work.
 
@@ -18,24 +18,24 @@ High-level features we plan on implementing.
     * [ ] Integration with screen readers
     * [x] Monochrome mode
     * [ ] High contrast theme
-    * [ ] Color blind themes
+    * [ ] Color-blind themes
 - [ ] Command interface
     * [ ] Command menu
     * [ ] Fuzzy search
 - [ ] Configuration (.toml based extensible configuration format)
-- [x] Console 
+- [x] Console
 - [ ] Devtools
-    * [ ] Integrated log 
-    * [ ] DOM tree view 
+    * [ ] Integrated log
+    * [ ] DOM tree view
     * [ ] REPL
 - [ ] Reactive state abstraction
-- [x] Themes 
-    * [ ] Customize via config 
+- [x] Themes
+    * [ ] Customize via config
     * [ ] Builtin theme editor
 
 ## Widgets
 
-Widgets are key to making user friendly interfaces. The builtin widgets should cover many common (and some uncommon) use-cases. The following is a list of the widgets we have built or are planning to build.
+Widgets are key to making user-friendly interfaces. The builtin widgets should cover many common (and some uncommon) use-cases. The following is a list of the widgets we have built or are planning to build.
 
 - [x] Buttons
     * [x] Error / warning variants
@@ -44,8 +44,8 @@ Widgets are key to making user friendly interfaces. The builtin widgets should c
 - [ ] Content switcher
 - [x] DataTable
     * [x] Cell select
-    * [ ] Row / Column select
-    * [ ] API to update cells / rows 
+    * [x] Row / Column select
+    * [ ] API to update cells / rows
     * [ ] Lazy loading API
 - [ ] Date picker
 - [ ] Drop-down menus
@@ -76,4 +76,3 @@ Widgets are key to making user friendly interfaces. The builtin widgets should c
     * [ ] Indentation guides
     * [ ] Smart features for various languages
     * [ ] Syntax highlighting
-