Remove more unexported sections

README.org

@@ -1706,28 +1706,6 @@ pairs.
 | renumber grep/occur matches | =\(.+:\)=                       | =\,(1+ \#)._= |
 |-----------------------------+---------------------------------+---------------|
 
-** [[https://github.com/Wilfred/deadgrep#readme][Deadgrep]]                                                        :noexport:
-:PROPERTIES:
-:CUSTOM_ID: sec:deadgrep
-:header-args:emacs-lisp: :tangle no :eval never-export
-:END:
-
-[[https://github.com/Wilfred/deadgrep#readme][Deadgrep]] uses [[https://github.com/BurntSushi/ripgrep#readme][ripgrep]] for superfast text searching in the default directory or
-the current [[https://en.wikipedia.org/wiki/Version_control][VCS]] directory tree.  Listing [[lst:bind-deadgrep-commands][setup =deadgrep= commands]] binds
-=deadgrep= globally to {{{kbd(M-s d)}}} and =deadgrep-edit-mode= locally to
-{{{kbd(C-c C-w)}}}.
-
-#+caption[Bind =deadgrep= commands]:
-#+caption: Bind =deadgrep= commands.
-#+name: lst:bind-deadgrep-commands
-#+begin_src emacs-lisp -n :results silent
-(when (and (ensure-package-installation 'deadgrep)
-           (fboundp 'deadgrep))
-  (keymap-set search-map "d" #'deadgrep)
-  (with-eval-after-load 'deadgrep
-    (keymap-set deadgrep-mode-map "C-c C-w" #'deadgrep-edit-mode)))
-#+end_src
-
 ** [[https://www.masteringemacs.org/article/searching-buffers-occur-mode][Searching and Editing in Buffers with Occur Mode]]
 :PROPERTIES:
 :CUSTOM_ID: sec:occur
@@ -2153,68 +2131,6 @@ configuration objectives:
                                LaTeX-section-label)))
 #+end_src
 
-*** [[https://gitlab.com/matsievskiysv/math-preview/-/blob/master/README.md][Math-preview]]                                                   :noexport:
-:PROPERTIES:
-:CUSTOM_ID: sec:math-preview
-:header-args:emacs-lisp: :tangle no
-:END:
-
-[[https://gitlab.com/matsievskiysv/math-preview/-/blob/master/README.md][Math-preview]] uses [[https://docs.mathjax.org/en/latest/][Mathjax-3]] to display [[https://www.latex-project.org/][LaTeX]], [[https://www.w3.org/Math/][MathML]],and [[http://asciimath.org/][asciimath]] in Emacs
-buffers with help of an external [[https://nodejs.org][node.js]] program.
-
-#+caption[Setup =math-preview=]:
-#+caption: Setup =math-preview=.
-#+name: lst:setup-math-preview
-#+begin_src emacs-lisp -n :results silent
-(when (ensure-package-installation 'math-preview)
-  (with-eval-after-load 'math-preview
-    ;; https://docs.mathjax.org/en/latest/input/tex/extensions/physics.html
-    (let ((physics (split-string "
-abs absolutevalue acomm acos acosecant acosine acot acotangent
-acsc admat anticommutator antidiagonalmatrix arccos arccosecant
-arccosine arccot arccotangent arccsc arcsec arcsecant arcsin
-arcsine arctan arctangent asec asecant asin asine atan atangent
-bmqty bqty Bqty bra braket comm commutator cos cosecant cosh
-cosine cot cotangent coth cp cross crossproduct csc csch curl dd
-derivative det determinant diagonalmatrix diffd differential div
-divergence dmat dotproduct dv dyad erf ev eval evaluated exp
-expectationvalue exponential expval fderivative fdv flatfrac
-functionalderivative grad gradient gradientnabla hypcosecant
-hypcosine hypcotangent hypsecant hypsine hyptangent
-identitymatrix Im imaginary imat innerproduct ip ket ketbra
-laplacian ln log logarithm matrixdeterminant matrixel
-matrixelement matrixquantity mdet mel mqty naturallogarithm norm
-op order outerproduct partialderivative paulimatrix pb
-pderivative pdv pmat pmqty Pmqty poissonbracket pqty Pr
-principalvalue Probability pv PV qall qand qas qassume qc qcc
-qcomma qelse qeven qfor qgiven qif qin qinteger qlet qodd qor
-qotherwise qq qqtext qsince qthen qty quantity qunless qusing
-rank Re real Res Residue sbmqty sec secant sech sin sine sinh
-smallmatrixquantity smdet smqty spmqty sPmqty svmqty tan tangent
-tanh tr Tr trace Trace va var variation vb vdot vectorarrow
-vectorbold vectorunit vmqty vnabla vqty vu xmat xmatrix
-zeromatrix zmat")))
-      (cl-pushnew `("physics" . ,physics)
-                  math-preview-tex-packages-autoload-packages))
-    (setq math-preview-raise 0.5
-          math-preview-scale 1
-          math-preview-tex-default-packages '("autoload" "ams" "physics"))
-    (let ((command (executable-find "~/node_modules/.bin/math-preview")))
-      (if command
-          (setq math-preview-command command)
-        ;; https://stackoverflow.com/a/17509764 answers:
-        ;; How to install an npm package from github directly?
-        (unless (file-directory-p "~/node_modules")
-          (make-directory "~/node_modules"))
-        (cl-destructuring-bind (exit-code output)
-            (shell-command-with-exit-code
-             "npm" "install"
-             "git+https://gitlab.com/matsievskiysv/math-preview.git")
-          (if (= 0 exit-code)
-              (message "%s" (string-trim output))
-            (error "%s" (string-trim output))))))))
-#+end_src
-
 *** TODO Improve the AUCTeX configuration slowly
 :PROPERTIES:
 :CUSTOM_ID: sec:setup-auctex-slowly