feat: Support MaxWidth < 0 for left-alignment

Author: hedyhli

README.md

@@ -272,6 +272,7 @@ index0shortcut = -1
 maxWidth = 70
 # width of each page is max(<terminalWidth>, maxWidth)
 # set to 0 to always use the terminal width.
+# set to negative X to use a maxWidth of X but disable centering.
 
 useCertificates = [
     # default: [] (see details below)

client.go

@@ -268,11 +268,12 @@ func (c *Client) ParseGeminiPage(page *Page) string {
 	}
 	width := termWidth
 	sides := 0
-	if c.conf.MaxWidth != 0 && width > c.conf.MaxWidth {
+	if c.conf.MaxWidth > 0 && width > c.conf.MaxWidth {
 		width = c.conf.MaxWidth
-		// sides := int((termWidth - width) / 2)
-		// XXX: Huh?
-		sides = termWidth - width
+		sides = int((termWidth - width) / 2)
+	}
+	if c.conf.MaxWidth < 0 && width > (-c.conf.MaxWidth) {
+		width = -c.conf.MaxWidth
 	}
 
 	preformatted := false

gelim.1

@@ -230,6 +230,8 @@ columns wide for gemtext documents, and centered.
 .P
 Set to \fI0\fR to always use the terminal width.
 .P
+Set to negative X to use a maxWidth of X but disable centering.
+.P
 For plain text documents, Nex directories, and gophermaps, the page will be
 centered based on the maximum width of the text in the document.
 .P

gelim.1.scd

@@ -147,6 +147,8 @@ Keys are case-insensitive.
 
 	Set to _0_ to always use the terminal width.
 
+	Set to negative X to use a maxWidth of X but disable centering.
+
 	For plain text documents, Nex directories, and gophermaps, the page will be
 	centered based on the maximum width of the text in the document.