Codespell fixes.

docs/how-to/make-per-application-backups.md

@@ -33,8 +33,8 @@ sudo borgmatic config generate --destination /etc/borgmatic.d/repo2.yaml
 ```
 
 <span class="minilink minilink-addedin">Prior to version 1.7.15</span> The
-command to generate configuation files was `generate-borgmatic-config` instead
-of `borgmatic config generate`.
+command to generate configuration files was `generate-borgmatic-config`
+instead of `borgmatic config generate`.
 
 When you set up multiple configuration files like this, borgmatic will run
 each one in turn from a single borgmatic invocation. This includes, by

docs/how-to/set-up-backups.md

@@ -125,7 +125,7 @@ sudo borgmatic config generate
 ```
 
 <span class="minilink minilink-addedin">Prior to version 1.7.15</span>
-Generate a configuation file with this command instead:
+Generate a configuration file with this command instead:
 
 ```bash
 sudo generate-borgmatic-config

docs/how-to/upgrade.md

@@ -41,8 +41,8 @@ borgmatic config generate --source config.yaml --destination config-new.yaml
 ```
 
 <span class="minilink minilink-addedin">Prior to version 1.7.15</span> The
-command to generate configuation files was `generate-borgmatic-config` instead
-of `borgmatic config generate`.
+command to generate configuration files was `generate-borgmatic-config`
+instead of `borgmatic config generate`.
 
 New options start as commented out, so you can edit the file and decide
 whether you want to use each one.