docs: help tags for neovim.io searches

runtime/doc/intro.txt

@@ -53,19 +53,33 @@ Nvim on the interwebs					*internet*
 - Nvim home page: https://neovim.io/
 - Vim FAQ: https://vimhelp.org/vim_faq.txt.html
 
-			*download* *upgrade* *ubuntu*
+			*download* *upgrade* *install* *ubuntu*
 To install or upgrade Nvim, you can...
 - Download a pre-built archive:
   https://github.com/neovim/neovim/releases
 - Use your system package manager:
   https://github.com/neovim/neovim/blob/master/INSTALL.md#install-from-package
+- Build from source:
+  https://github.com/neovim/neovim/blob/master/INSTALL.md#install-from-source
 
 			*bugs* *bug-report* *feature-request*
 Report bugs and request features here: https://github.com/neovim/neovim/issues
 Be brief, yet complete.  Always give a reproducible example and try to find
-out which settings or other things trigger the bug.
+out which settings or other things trigger the bug. If Nvim crashed, try to
+get a backtrace (see |dev-tools-backtrace|).
 
-If Nvim crashes, try to get a backtrace.  See |debug.txt|.
+			*uninstall*
+To un-install Nvim:
+- If you downloaded a pre-built archive or built Nvim from source (e.g. `make
+  install`), just delete its files, typically located in: >
+  /usr/local/bin/nvim
+  /usr/local/share/nvim
+<
+- If you installed via package manager, read your package manager's
+  documentation. Common examples:
+  - APT (Debian, Ubuntu, …): `apt-get remove neovim`
+  - Homebrew (macOS): `brew install neovim`
+  - Scoop (Windows): `scoop install neovim`
 
 ==============================================================================
 Sponsor Vim/Nvim development				*sponsor* *register*

runtime/doc/provider.txt

@@ -193,7 +193,7 @@ registers. Nvim looks for these clipboard tools, in order of priority:
   - xclip (if $DISPLAY is set)
   - lemonade (for SSH) https://github.com/pocke/lemonade
   - doitclient (for SSH) https://www.chiark.greenend.org.uk/~sgtatham/doit/
-  - win32yank (Windows)
+  - *win32yank* (Windows)
   - putclip, getclip (Windows) https://cygwin.com/packages/summary/cygutils.html
   - clip, powershell (Windows) https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/clip
   - termux (via termux-clipboard-set, termux-clipboard-set)

runtime/doc/sign.txt

@@ -10,7 +10,7 @@ Sign Support Features				*sign-support*
                                       Type |gO| to see the table of contents.
 
 ==============================================================================
-1. Introduction					*sign-intro* *signs*
+1. Introduction					*sign-intro* *signs* *gutter*
 
 When a debugger or other IDE tool is driving an editor it needs to be able
 to give specific highlights which quickly tell the user useful information