update urls (#24)

* update urls

* Update source/ch-git-github.ptx

* Removal of word repetition (#26)

Changed "of of" to "of"

---------

Co-authored-by: DanielHodgins <121420574+DanielHodgins@users.noreply.github.com>

README.md

@@ -14,5 +14,5 @@ public use under an open license.
 
 ## Copyright
 
-This work is copyright 2023 Steven Clontz, available for free and public use
+This work is copyright 2023-2024 Steven Clontz, available for free and public use
 under an [open license](./LICENSE.md).

publication/publication.ptx

@@ -113,7 +113,7 @@
     javascript, etc).  -->
     <calculator model="none" activecode="none" />
     <!-- Set the base URL of where the online version is hosted to have links in other formats -->
-    <baseurl href="https://g4m.clontz.org/"/>
+    <baseurl href="https://g4m.code4math.org/"/>
     <!-- Control behavior of online WeBWorK, per type: -->
     <webwork
       inline="dynamic"

source/ch-git-github.ptx

@@ -25,7 +25,7 @@ and even modify it for your purposes if you wanted.
 Two core concepts of Git are <term>commits</term> (illustrated
 in <xref ref="fig-git-branches"/> by circles) and <term>branches</term>
 (illustrated in <xref ref="fig-git-branches"/> by lines). A
-commit represents the state of of your project at a particular
+commit represents the state of your project at a particular
 point in its history. Branches allow this history to not be
 linear: you can branch off to experiment on a particular new
 feature, then merge this <q>feature branch</q> back into
@@ -96,9 +96,9 @@ efficiently.
 An example of a project using Git and GitHub is the
 document you're reading right now!
 This book is open-sourced and shared at
-<url href="https://github.com/StevenClontz/github-for-mathematicians"/>,
+<url href="https://github.com/code4mathorg/github-for-mathematicians"/>,
 and was authored completely in a web browser using only the GitHub features
 we will explore together in this handbook.
         </p>
     </section>
-</chapter>
+</chapter>