uses simpler branch names in merge

basics.html

@@ -803,8 +803,7 @@
             ```bash
             git remote add alice https://...
             git fetch alice
-            git checkout master
-            git merge alice/topic/feature
+            git merge alice/master
             # fix conflicts
             git push
             ```
@@ -813,7 +812,6 @@
 
             ```bash
             git fetch upstream
-            git checkout topic/feature
             git merge origin/master
             # fix conflicts
             git push
@@ -877,7 +875,7 @@
             ```bash
             git remote add alice https://...
             git fetch alice
-            git rebase master alice/topic/feature
+            git rebase master alice/master
             # fix conflicts
             git push
             # close merge request
@@ -887,7 +885,7 @@
 
             ```bash
             git fetch upstream
-            git rebase origin/master topic/feature
+            git rebase origin/master master
             # fix conflicts
             # force push because branch history changed
             git push --force