docs: init: fix markup/typos

src/borg/archiver.py

@@ -1765,32 +1765,33 @@ class Archiver:
         Encryption modes
         ++++++++++++++++
 
-        repokey and keyfile use AES-CTR-256 for encryption and HMAC-SHA256 for
+        `repokey` and `keyfile` use AES-CTR-256 for encryption and HMAC-SHA256 for
         authentication in an encrypt-then-MAC (EtM) construction. The chunk ID hash
         is HMAC-SHA256 as well (with a separate key).
         These modes are compatible with borg 1.0.x.
 
-        repokey-blake2 and keyfile-blake2 are also authenticated encryption modes,
+        `repokey-blake2` and `keyfile-blake2` are also authenticated encryption modes,
         but use BLAKE2b-256 instead of HMAC-SHA256 for authentication. The chunk ID
         hash is a keyed BLAKE2b-256 hash.
-        These modes are new and not compatible with borg 1.0.x.
+        These modes are new and *not* compatible with borg 1.0.x.
 
-        "authenticated" mode uses no encryption, but authenticates repository contents
+        `authenticated` mode uses no encryption, but authenticates repository contents
         through the same keyed BLAKE2b-256 hash as the other blake2 modes (it uses it
         as chunk ID hash). The key is stored like repokey.
         This mode is new and not compatible with borg 1.0.x.
 
-        "none" mode uses no encryption and no authentication. It uses sha256 as chunk
+        `none` mode uses no encryption and no authentication. It uses sha256 as chunk
         ID hash. Not recommended, rather consider using an authenticated or
         authenticated/encrypted mode.
         This mode is compatible with borg 1.0.x.
 
         Hardware acceleration will be used automatically.
 
-        On modern Intel/AMD CPUs (except very cheap ones), AES is usually hw
-        accelerated. BLAKE2b is faster than sha256 on Intel/AMD 64bit CPUs.
+        On modern Intel/AMD CPUs (except very cheap ones), AES is usually
+        hardware-accelerated. BLAKE2b is faster than SHA256 on Intel/AMD 64bit CPUs,
+        which makes `authenticated` faster than `none`.
 
-        On modern ARM CPUs, NEON provides hw acceleration for sha256 making it faster
+        On modern ARM CPUs, NEON provides hardware acceleration for SHA256 making it faster
         than BLAKE2b-256 there.
         """)
         subparser = subparsers.add_parser('init', parents=[common_parser], add_help=False,
@@ -1804,7 +1805,7 @@ class Archiver:
         subparser.add_argument('-e', '--encryption', dest='encryption',
                                choices=('none', 'keyfile', 'repokey', 'keyfile-blake2', 'repokey-blake2', 'authenticated'),
                                default=None,
-                               help='select encryption key mode (default: "%(default)s")')
+                               help='select encryption key mode')
         subparser.add_argument('-a', '--append-only', dest='append_only', action='store_true',
                                help='create an append-only mode repository')