Add --terminal-prefix option

[johanmalm]

@01micko Any chance you could review this one.
After this patch I'll set the version to 0.1.0

[01micko]

Other than the line comments LGTM - tested used 'alacritty -e' and worked for Htop :)

[01micko]

At least my version pf scdoc doesn't like this syntax
Error msg:

[4/12] Generating data/labwc-menu-gene...eson to capture output, to feed input)
FAILED: data/labwc-menu-generator.1 
/usr/bin/meson --internal exe --capture data/labwc-menu-generator.1 --feed ../data/labwc-menu-generator.1.scd -- /usr/bin/scdoc
--- stderr ---
Error at 41:3: Expected ``` and a newline to begin literal block

I just patched it to get it to compile:

--- labwc-menu-generator.1.scd.orig	2024-06-25 16:39:50.319997984 +1000
+++ labwc-menu-generator.1.scd	2024-06-25 16:24:34.067284083 +1000
@@ -37,8 +37,16 @@
 	Output in pipemenu format
 
 *-t, --terminal-prefix <command>*
-	Specify prefix for Terminal=true entries, for example `foot` or
-	`xterm -e`
+	Specify prefix for Terminal=true entries, for example 
+	
+	```
+	foot
+	```
+	
+	or
+	```
+	xterm -e
+	```
 
 # AUTHORS

[01micko]

Actually ignore the newlines in above patch, needless. EDIT: Sorry, s/newlines/empty lines/, :face_palm:

[01micko]

Or just use asterisks instead of back ticks. I've no set preference, didn't install so didn't test the manpage live but I don't see an issue either way.

[johanmalm]

Thanks. Good catch. Have changed to normal apostrophe. Have also added scdoc to the workflow.

[01micko]

Aha, so the CI doesn't detect the scdoc problem because it's an optional dep and CI doesn't have it! I can't push a fix for that so that may require a fixup.