Add Emacs desktop provisioning and dev toolchain packages

Install Emacs and copy the desktop .emacs.d config so the editor setup is managed with the rest of desktop dotfiles. Add vterm/build/debug dependencies plus C/C++ and Go tooling needed by the configured workflow.

dotfiles/desktop/.emacs.d/snippets/markdown-mode/a

@@ -0,0 +1,3 @@
+#name : a
+# --
+[${1}](${2})${0}

dotfiles/desktop/.emacs.d/snippets/markdown-mode/img

@@ -0,0 +1,9 @@
+#name : img snippet
+# --
+
+<img
+  class="centered"
+  src="${1:foo.png}"
+  alt="${2:alt img text}"
+/>
+$0

dotfiles/desktop/.emacs.d/snippets/markdown-mode/me

@@ -0,0 +1,3 @@
+# name : me
+# --
+[@skybert](https://skybert.net) ${1:says:}$0

dotfiles/desktop/.emacs.d/snippets/markdown-mode/pa

@@ -0,0 +1,17 @@
+#name : pelican article
+# --
+title: ${1:`(s-replace "-" " " (file-name-base (buffer-file-name)))`}
+date: ${2:`(format-time-string "%Y-%m-%d" (current-time))`}
+category: ${3:`(file-name-nondirectory
+ (substring
+  (file-name-directory (buffer-file-name))
+  0
+  (- (length (file-name-directory (buffer-file-name))) 1)
+  ))`}
+tags: ${4:`(file-name-nondirectory
+ (substring
+  (file-name-directory (buffer-file-name))
+  0
+  (- (length (file-name-directory (buffer-file-name))) 1)
+  ))`}
+$0

dotfiles/desktop/.emacs.d/snippets/markdown-mode/src

@@ -0,0 +1,6 @@
+#name : src code snippet
+# --
+
+\`\`\`${1:text}
+$0
+\`\`\`

dotfiles/desktop/.emacs.d/snippets/markdown-mode/st

@@ -0,0 +1,4 @@
+#name : strong element
+# --
+
+<strong>${1:text}</strong>$0