nvim: add page (#2264)

pages/common/nvim.md

@@ -0,0 +1,36 @@
+# nvim
+
+> Neovim, a programmer's text editor based on Vim, provides several modes for different kinds of text manipulation.
+> Pressing `i` enters edit mode. `<Esc>` goes back to normal mode, which doesn't allow regular text insertion.
+
+- Open a file:
+
+`nvim {{file}}`
+
+- Enter text editing mode (insert mode):
+
+`<Esc>i`
+
+- Copy ("yank") or cut ("delete") the current line (paste it with `P`):
+
+`<Esc>{{yy|dd}}`
+
+- Undo the last operation:
+
+`<Esc>u`
+
+- Search for a pattern in the file (press `n`/`N` to go to next/previous match):
+
+`<Esc>/{{search_pattern}}<Enter>`
+
+- Perform a regex substitution in the whole file:
+
+`<Esc>:%s/{{pattern}}/{{replacement}}/g<Enter>`
+
+- Save (write) the file, and quit:
+
+`<Esc>:wq<Enter>`
+
+- Quit without saving:
+
+`<Esc>:q!<Enter>`