Fix Typo in README.rst

Converted from getsops/sops@cbee268

Co-authored-by: Lukas Schröder <122912915+inverted-tree@users.noreply.github.com>
Signed-off-by: Lukas Schröder <122912915+inverted-tree@users.noreply.github.com>
Signed-off-by: Felix Fontein <felix@fontein.de>

Author: felixfontein

content/en/docs/_index.md

@@ -261,7 +261,7 @@ You can use SSH public keys (`ssh-ed25519 AAAA...`, `ssh-rsa AAAA...`)
 as age recipients when encrypting a file.
 When decrypting a file, SOPS will look for `~/.ssh/id_ed25519` and falls back to
 `~/.ssh/id_rsa`. You can specify the location of the private key manually by setting
-the environment variableuse **SOPS_AGE_SSH_PRIVATE_KEY_FILE**.
+the environment variable **SOPS_AGE_SSH_PRIVATE_KEY_FILE**.
 
 Note that only `ssh-rsa` and `ssh-ed25519` are supported.