Address review of the BON8 documentation

Restore the correct statement that marker bytes cannot begin a UTF-8 character (0x80..0xBF occur in valid UTF-8 as continuation bytes), and reword two sentences.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

docs/mkdocs/docs/features/binary_formats/bon8.md

@@ -1,7 +1,7 @@
 # BON8
 
 BON8 (Binary Object Notation 8) is a compact binary serialization format for JSON values. It uses byte values that
-cannot occur in valid UTF-8 as type markers, so strings are stored as plain UTF-8 without a length prefix: a string
+cannot begin a UTF-8 character as type markers, so strings are stored as plain UTF-8 without a length prefix: a string
 ends at the first byte that cannot continue it. Integers from -10 to 39, `true`, `false`, `null`, and the floating-point
 values -1.0, 0.0, and 1.0 take a single byte, and arrays and objects with up to four elements need no terminator.
 
@@ -12,7 +12,7 @@ values -1.0, 0.0, and 1.0 take a single byte, and arrays and objects with up to
 
 ## Byte layout
 
-BON8 exploits the fact that some byte values can never occur in valid UTF-8. These bytes serve as *type markers*, so strings can be stored as plain UTF-8 without a length prefix: a string ends at the first byte that is not part of a valid UTF-8 character: a marker byte, or a lead byte 0xC2..0xF7 followed by a byte outside 0x80..0xBF (often the marker of the next value). Small integers, `true`, `false`, `null`, and a few common floats are a single byte. Arrays and objects are introduced by a marker; those with up to four elements encode their size in the marker and need no terminator, while larger ones are closed by the end marker `0xFE`.
+BON8 exploits the fact that some byte values can never start a UTF-8 character. These bytes serve as *type markers*, so strings can be stored as plain UTF-8 without a length prefix: a string ends at the first byte that cannot continue it: a marker byte, or a lead byte 0xC2..0xF7 followed by a byte outside 0x80..0xBF. The ending byte is often the marker of the next value. Small integers, `true`, `false`, `null`, and a few common floats are a single byte. Arrays and objects are introduced by a marker; those with up to four elements encode their size in the marker and need no terminator, while larger ones are closed by the end marker `0xFE`.
 
 Consider the following JSON value (shown formatted for readability):
 

docs/mkdocs/docs/home/exceptions.md

@@ -380,9 +380,9 @@ An unexpected byte was read in a [binary format](../features/binary_formats/inde
 A string could not be read from a [binary format](../features/binary_formats/index.md): either a value that is not a
 string was read where one was required (for instance as a map key), the string's length specification is invalid, or
 the string's bytes are not valid UTF-8 and the `error_handler` parameter of the corresponding `from_*` function is
-set to `strict`. By default (`error_handler_t::keep`), the bytes of a string are not checked for valid UTF-8 on read
-for the formats whose `from_*` function has an `error_handler` parameter;
-see the ill-formed UTF-8 notes on the individual [binary format](../features/binary_formats/index.md) pages for how
+set to `strict`. By default (`error_handler_t::keep`), the bytes of a string are not checked for valid UTF-8 on read.
+This applies to the `from_*` functions that have an `error_handler` parameter; `from_bon8` does not have one.
+See the ill-formed UTF-8 notes on the individual [binary format](../features/binary_formats/index.md) pages for how
 such a string is handled depending on `error_handler`.
 [`from_bon8()`](../api/basic_json/from_bon8.md) never throws this exception: BON8 non-string keys and ill-formed UTF-8
 are reported as [parse_error.112](#jsonexceptionparse_error112).