Fix typos in the 3.0 migration guide

Signed-off-by: David Horstmann <david.horstmann@arm.com>
diff --git a/docs/3.0-migration-guide.md b/docs/3.0-migration-guide.md
index 42af9db..a1747bc 100644
--- a/docs/3.0-migration-guide.md
+++ b/docs/3.0-migration-guide.md
@@ -349,7 +349,7 @@
 | `mbedtls_sha512_finish_ret`    | `mbedtls_sha512_finish`    |
 | `mbedtls_sha512_ret`           | `mbedtls_sha512`           |
 
-To migrate to the this change the user can keep the `*_ret` names in their code
+To migrate to this change the user can keep the `*_ret` names in their code
 and include the `compat_2.x.h` header file which holds macros with proper
 renaming or to rename those functions in their code according to the list from
 mentioned header file.
@@ -409,7 +409,7 @@
 Previously, the documentation didn't state explicitly if it was OK to call
 `mbedtls_cipher_check_tag()` or `mbedtls_cipher_write_tag()` directly after
 the last call to `mbedtls_cipher_update()` — that is, without calling
-`mbedtls_cipher_finish()` in-between. If you code was missing that call,
+`mbedtls_cipher_finish()` in-between. If your code was missing that call,
 please add it and be prepared to get as much as 15 bytes of output.
 
 Currently the output is always 0 bytes, but it may be more when alternative
@@ -422,7 +422,7 @@
 
 They are already niche or obsolete and most of them are weak or broken. For
 those reasons possible users should consider switching to modern and safe
-alternatives to be found in literature.
+alternatives to be found in the literature.
 
 ### Deprecated functions were removed from cipher
 
@@ -806,11 +806,11 @@
 In Mbed TLS 2.x, users would observe later calls overwriting
 the effect of earlier calls, with the prevailing PSK being
 the one that has been configured last. In Mbed TLS 3.0,
-calling `mbedtls_ssl_conf_[opaque_]psk()` multiple times
+calling `mbedtls_ssl_conf_psk[_opaque]()` multiple times
 will return an error, leaving the first PSK intact.
 
 To achieve equivalent functionality when migrating to Mbed TLS 3.0,
-users calling `mbedtls_ssl_conf_[opaque_]psk()` multiple times should
+users calling `mbedtls_ssl_conf_psk[_opaque]()` multiple times should
 remove all but the last call, so that only one call to _either_
 `mbedtls_ssl_conf_psk()` _or_ `mbedtls_ssl_conf_psk_opaque()`
 remains.