README: tiny enhancements

README.org

@@ -292,14 +292,19 @@ prefix them with =<insert>=. Example: =<insert>-= inserts a =-= and
 To draw a rectangle in one shot, select a rectangular region with
 =C-SPC= or =C-x SPC= and move the cursor.
 
+You may also use =S-<arrow>= (=<arrow>= beeing any of the 4
+directions) to extend the selection. The buffer grows as needed with
+white spaces to accomodate the selection. Selection extension mode is
+active when =shift-select-mode= is non-nil.
+
 If needed, change the brush with any of
  =- + = # <delete>=
 
 then hit
 - =    r= to draw a rectangle inside the selection
-- =  S-R= to draw a rectangle ouside the selection
+- =  S-R= to draw a rectangle outside the selection
 - =  C-r= to overwrite a rectangle inside the selection
-- =C-S-R= to overwrite a rectangle ouside the selection
+- =C-S-R= to overwrite a rectangle outside the selection
 
 [[file:images/draw-rectangle.png]]
 
@@ -556,14 +561,51 @@ Why activate =whitespace-mode= while in =uniline-mode=? Because
 =uniline-mode= creates a lot of white-spaces to implement an infinite
 buffer. And it is funny to look at this activity.
 
-To make them fully compatible, disable the newline visualization:
+To make =uniline-mode= and =whitespace-mode= fully compatible, disable
+the newline visualization:
 
 - =M-x customize-variable whitespace-style=
 - uncheck =(Mark) NEWLINEs=
 
 This is due to a glitch in =move-to-column= when a visual property is
 attached to newlines. And =uniline-mode= makes heavy use of =move-to-column=.
 
+** Compatibility with Org Mode
+You may want to customize the shift extension mode in =Org Mode=. This
+is because =Org Mode= preempts =shift-select-mode= for other useful
+purposes. Just type:
+
+#+begin_example
+M-x customize-variable org-support-shift-select
+#+end_example
+
+and choose "when outside special context", which sets it to =t=.
+
+You then get the shift-selection from =Org Mode=, not from =Uniline=. The
+difference is that the =Uniline='s one handles the infinite-ness of the
+buffer.
+
+Other than that, =Uniline= is compatible with =Org Mode=
+
+** What about =\t= tabs?
+Some files may contain tabs (the character =\t=). Those include
+programming code (Python, Perl, C++, D, Rust, JavaScript and so on).
+
+When =Uniline= draws something in the middle of a tab, it first
+converts it to spaces, then proceeds as usual. This process is
+invisible. So be cautious if tabs have a special meaning in the file.
+
+One way to see what is going on, is to activate the =whitespace-mode=.
+
+** What about =^L= page separation?
+=Uniline= does not work well with =^L= (page separation)
+character. Nore with similar characters, like =^T=. When trying to
+draw a line over such a character, the cursor may get stuck. This is
+because those characters occupy twice the width of a normal character.
+
+Just try to get away from =^L=, =^T= and such when drawing with
+=Uniline=.
+
 * Exotic environments
 ** Emacs on the Linux console
 Linux consoles are the 7 non-graphic screens which can be accessed
@@ -598,13 +640,13 @@ for =C-<insertchar>=, for example with =use-package= in your
 #+end_example
 
 ** Emacs on Windows
-On Windows the only native monospaced fonts are Lucida Console and
-Courier New. They are not monospaced for the Unicodes used by
+On Windows the only native monospaced fonts are =Lucida Console= and
+=Courier New=. They are not monospaced for the Unicodes used by
 =Uniline=.
 
-Often, the Cosolas font is present on Windows. It supports quite well
+Often, the =Consolas= font is present on Windows. It supports quite well
 the required Unicodes to draw lines. A few glyphs produce unaligned
-result though. They should be avoided under Consolas: =△▶▹◇◆=
+result though. They should be avoided under =Consolas=: =△▶▹◇◆=
 
 Of course, other fonts may be installed. It is quite easy.
 
@@ -703,6 +745,12 @@ In this example, =C-<insert>= was choosen. You can use whatever keys combination
 - =ibm-box-drawing-hydra.el=: keyboard interface to insert UNICODE
   box-drawing characters one at a time
 
+- =org-excalidraw=: integrate SVG images generated by excalidraw into
+  Org Mode
+
+- =rcd-box=: create tables surrounded by box-drawing characters from
+  Lisp descriptions
+
 * Author, contributors
 - Thierry Banel, author
 - Joost Kremers https://github.com/joostkremers found a bug in the