add more key combinations to cheat sheet

README.md

@@ -80,7 +80,9 @@ This is how it looks like:
 
 ## Command cheat sheet
 
-### Vim/Neovim
+### Neovim
+
+Some of these are plain Vim commands, other specific to Neovim.
 
 #### Basics
 
@@ -102,6 +104,8 @@ This is how it looks like:
 - `w` move to **start of next word** (ignores punctuation due to remap)
 - `e` move to **end of next word** (ignores punctuation due to remap)
 - `b` move to **start of previous word** (ignores punctuation due to remap)
+- `Ctrl`+`d` scroll **down** 1/2 page while keeping the cursor centered
+- `Ctrl`+`u` scroll **up** 1/2 page while keeping the cursor centered
 
 ##### Code editing
 
@@ -113,6 +117,12 @@ This is how it looks like:
 - `A` insert mode at the **end of the line**
 - `o` insert mode a line **below** the cursor
 - `O` insert mode a line **above** the cursor
+- `s` delete character and replace (substitute) it
+- `cw` replace the current word
+- `yy` copy (yank) the current line
+- `p` paste yanked line below
+- `P` paste yanked line above
+- `"3p` redo (put) e.g. your third last delete [source](https://www.reddit.com/r/neovim/comments/18ri1bm/its_been_like_10_years_and_i_just_learned_that/)
 
 ##### Visual mode
 
@@ -132,7 +142,7 @@ This is how it looks like:
 - `Ctrl`+`wq` close window
 - `Ctrl`+`ws` split window **horizontally**
 - `Ctrl`+`wv` split window **vertically**
-- `Ctrl`+`<h/j/k/l>` switch between split windows
+- `Ctrl`+`<h/j/k/l>` move between split windows
 - `Ctrl`+`w=` equalize split window width and height
 
 ##### Buffer navigation