replace dead link (#1717)

tshepang · web-flow · commit a0f596fbbfbc · 2023-07-03T10:34:58.000+09:00
diff --git a/src/appendix/background.md b/src/appendix/background.md
@@ -300,7 +300,7 @@ does not.
 
 > Thanks to `mem`, `scottmcm`, and `Levi` on the official Discord for the
 > recommendations, and to `tinaun` for posting a link to a [twitter thread from
-> Graydon Hoare](https://twitter.com/graydon_pub/status/1039615569132118016)
+> Graydon Hoare](https://web.archive.org/web/20181230012554/https://twitter.com/graydon_pub/status/1039615569132118016)
 > which had some more recommendations!
 >
 > Other sources: https://gcc.gnu.org/wiki/ListOfCompilerBooks

Original file line number	Diff line number	Diff line change
`@@ -300,7 +300,7 @@ does not.`
`300`	`300`
`301`	`301`	> Thanks to `mem`, `scottmcm`, and `Levi` on the official Discord for the
`302`	`302`	> recommendations, and to `tinaun` for posting a link to a [twitter thread from
`303`		`-> Graydon Hoare](https://twitter.com/graydon_pub/status/1039615569132118016)`
	`303`	`+> Graydon Hoare](https://web.archive.org/web/20181230012554/https://twitter.com/graydon_pub/status/1039615569132118016)`
`304`	`304`	`> which had some more recommendations!`
`305`	`305`	`>`
`306`	`306`	`> Other sources: https://gcc.gnu.org/wiki/ListOfCompilerBooks`